How to Make Inter‑Municipal Co‑operation Work

3. Country Snapshots of inter-municipal co-operation frameworks in OECD countries and selected accession countries

Abstract

This section presents country snapshots of the legal and institutional frameworks for inter-municipal co-operation across OECD and accession countries. Each snapshot provides a concise overview of the main legal bases, forms, and recent developments that enable or shape co-operation among municipalities, as well as the principal areas in which inter-municipal co-operation takes place. Where available, it also outlines the mechanisms used to finance these co-operative arrangements.

Introduction

These snapshots highlight the diversity of approaches to organising, formalising, and funding inter-municipal co-operation across governance systems, ranging from flexible, voluntary agreements to highly institutionalised joint entities. The list of regulations, co-operation types, and fields presented here is not exhaustive, and in many cases sector-specific laws further complement the general frameworks described. In federal countries, where the regulation of inter-municipal co-operation often falls within the jurisdiction of individual states or regions, the examples included are intended to illustrate national trends rather than provide comprehensive coverage.

Australia

Since local government is regulated under state legislation rather than federal law in Australia, the legal framework for inter-municipal co-operation is shaped by state-specific legislation, with no overarching national regulation. While inter-municipal co-operation is encouraged and facilitated across all Australian states and territories, the extent and nature of regulation vary. Each state has its own set of provisions and frameworks that govern how local councils can collaborate, defined in local government acts and sectorial regulation (e.g. water, waste). These frameworks differ in terms of the scope, formality, and mandates for co-operation but overall, inter-municipal co-operation is flexible and functional (Sansom, 2019[1]). The strongest and most formal arrangements (e.g. statutory joint organisations) are found in New South Wales and Queensland, while other states rely more on voluntary alliances and shared service models (Morgan et al., 2024[2]). Strengthening inter-municipal co-operation is foreseen in several states, such as Tasmania where the local government sector is under review. Inter-municipal co-operation is a key consideration of this review given the potential cost, capability, and service delivery benefits it could help achieve (Hyslop S. et al., 2022[3]; Morgan et al., 2024[2]).

Existing models for inter-municipal co-operation around Australia are extremely diverse, ranging from the most flexible to more formalised co-operation bodies. They include, for example:

• Shared services agreements: local councils jointly procure goods or deliver administrative services (e.g. staff, IT, audit, building inspection) to achieve economies of scale. This form is widely used in regional and rural areas where capacity is limited.

• Voluntary associations and Regional Organisations of Councils (ROCs): formalised voluntary associations of local governments within a region but without a separate legal personality. They operate under mutual agreements, often supported by state governments, to co‑ordinate economic development, infrastructure, environmental management, or service delivery (e.g. Western Australia).

• Joint authorities, jointly-owned entities or statutory regional bodies: entail the collective establishment of a new entity or organisation to deliver a core local government service or infrastructure to participating councils (e.g. waste, water, transport). They are created under state legislation and have their own legal status and governing boards appointed by participating councils.

• Regional planning partnerships and joint development initiatives. In some states (notably NSW and Queensland), councils form Joint Organisations of Councils (JOs) or Regional Planning Partnerships, legally recognised under state law to co‑ordinate infrastructure, land-use, and economic strategies at a metropolitan or regional scale.

At the metropolitan level, governance arrangements in Australia are highly diverse, with numerous collaborative platforms such as the Inner Melbourne Action Plan (IMAP) Councils, the Metropolitan Transport Forum (MTF) in Melbourne, and the Council of Mayors in South East Queensland (Butt et al., 2020[4]). However, most metropolitan arrangements remain voluntary and informal (“soft co‑ordination”), focusing primarily on advocacy and strategic planning rather than joint service delivery. They typically have limited budgets and authority and depend heavily on state government frameworks and incentives. As a result, Australia’s metropolitan regions continue to be characterised by fragmented local government boundaries and overlapping jurisdictions, which impede co‑ordinated responses to major infrastructure, planning and environmental challenges. Future reforms will need to address issues of legitimacy, territorial fit and decision making authority in order to enhance collaboration at the metropolitan scale (Butt et al., 2020[4]).

Austria

The Austrian Federal Constitution (B-VG) guarantees municipal self-government (Article 116) and explicitly authorises municipalities to associate voluntarily to perform joint tasks (Article 116a). The 2011 amendment to the Federal Constitutional Law (BGBl I 60/2011) broadened these co-operation options, allowing municipalities to create multi-purpose associations and to co‑operate across Land (state) borders. While the constitutional framework is federal, the detailed rules and procedures for establishing and governing inter-municipal co-operation are defined in the municipal laws of each Land.

Forms of inter-municipal co-operation vary widely in scope and degree of institutionalisation. They range from informal or project-based collaboration to the formal and legally binding creation of multi-purpose public association (LOGOV/KDZ, 2021[5]; OECD/UCLG, 2022[6]).

• Informal or project-based co-operation includes networks, working groups, or joint participation in regional or EU-funded programmes. These arrangements have no legal personality, rely on voluntary co‑ordination, and typically address shared objectives such as regional planning, tourism, or economic development. They are flexible and easily dissolved.

• Administrative co-operations (Verwaltungsgemeinschaften or Verwaltungsverbände) allow municipalities to jointly perform specific administrative tasks such as registry functions, accounting, or building inspection without creating a new legal entity. Recognised in several Land laws, they enhance efficiency by sharing staff and resources.

• Under private law, municipalities may jointly establish limited liability companies (GmbH) or other entities to manage services of a commercial or utility nature, including waste management, water, energy, or business park development. These entities operate under private law and cannot exercise core public powers.

• The most formal type of co-operation is through local authority associations under public law (Gemeindeverbände), which are public-law corporations with their own governance, budget, and assets. Traditionally single-purpose (e.g. for water or waste management), since the 2011 constitutional amendment, municipalities may also form multi-purpose associations (Mehrzweckverbände) to jointly deliver a broader range of services such as planning, social welfare, and local development.

  The 2017 Fiscal Equalisation Act (FAG) further reinforced the ability of municipalities to engage in inter-municipal associations. In 2022, there were around 766 municipal associations, including 49% in the education sector (school community associations), 25% for administrative purposes (citizenship and registry offices), 9% in the cultural sector (music school associations) and the remaining in the social assistance and local transport sectors (OECD/UCLG, 2022[6]).

Belgium

Article 162 of the Belgian Constitution sets out general principles of provincial and municipal institutions and delegates to regional legislatures (Flemish, Walloon, Brussels) the authority to regulate local governance. municipalities have the right to form associations to jointly manage matters of local interest. This right is implemented through regional legislation, with Flanders, Wallonia and the Brussels-Capital Region each setting its own rules and frameworks. As a result, inter-municipal co-operation varies across regions, reflecting distinct governance traditions and local priorities.

Forms of co-operation range from informal partnerships to legally established inter-municipal entities. These arrangements enable municipalities to share resources, deliver joint services and implement development projects.

A common and long-standing form of inter-municipal co-operation across Belgium is the inter-municipal company (intercommunale). While the concept applies nationwide, each region regulates it differently. Intercommunales generally take the legal form of a limited liability co‑operative company (société coopérative à responsabilité limitée), whose shareholders are mainly municipalities and other public bodies. They operate within specific municipal territories or at regional scale, providing essential services in areas such as water, energy, waste, hygiene, funerary services, telecommunications and cable television (CoE - Congress of Local and Regional Authorities, 2022[7]; OECD, 2024[8]; OECD/UCLG, 2022[6]).

• In Flanders, there are five legal forms of inter-municipal co-operation: the inter-local association (interlokale vereniging), the project association (projectvereniging), the service-providing association (dienstverlenende vereniging), the association with a specific assignment (vereniging met een specifiek doel), and the association with a specific assignment and private sector participation. These forms differ in their governance, financial autonomy, and capacity to engage private partners.

• In Wallonia, inter-municipal co-operation is governed by the Code de la Démocratie Locale et de la Décentralisation (CDLD). Walloon municipalities commonly establish inter-municipal entities (intercommunales) to manage services such as water supply, energy distribution, waste management, healthcare and economic development. Two categories exist: “pure public inter-municipalities” (intercommunales pures de gestion publique) composed solely of public partners, and “mixed inter-municipalities” (intercommunales mixtes) that allow limited private participation. Wallonia also encourages more flexible project-based co-operation through syndicats d’études and partnerships agreements (conventions de partenariat).

• In the Brussels-Capital Region, inter-municipal co-operation reflects the city-region’s compact scale (19 municipalities) and strong regional competencies. Intercommunales bruxelloises are active mainly in utilities and shared urban services, such as Vivaqua (water), Hydria (wastewater treatment) and Sibelga (energy distribution). Co-operation is reinforced through regional co‑ordination mechanisms and joint agencies linking municipalities with the regional administration (OECD, 2024[8]).

Brazil

In Brazil, the legal framework for inter-municipal co-operation is primarily defined at the federal level, providing a clear and unified basis for municipalities to collaborate through formalised arrangements. The 1988 Federal Constitution recognises municipalities as autonomous entities and explicitly allows them to associate to manage public services of common interest. This constitutional foundation is operationalised through Federal Law No. 11.107/2005 (Public Consortia Law) and its regulatory Decree No. 6.017/2007, which establish the legal regime for inter-municipal co-operation, particularly through public consortia (consórcios públicos). This framework provides legal certainty, standardised procedures and a broad scope for co-operation across sectors such as health, waste management, water, transport and regional development. In parallel, other forms of co-operation – such as municipal associations – exist under private law, offering additional flexibility but with less formalised governance and fewer public powers.

Existing models of inter-municipal co-operation in Brazil are diverse, but largely structured around two main categories:

• Public consortia (consórcios públicos): the most institutionalised and widespread form of inter-municipal co-operation, regulated by federal law. These entities can be established either under public law (as public associations with legal personality) or private law, and may include municipalities, states and, in some cases, the federal government. Public consortia have their own governance bodies, budgets and staff, and can exercise delegated public functions, enter contracts, manage services and access public funding. They are widely used in sectors requiring scale and co-ordination, particularly healthcare (e.g. SUS service provision), solid waste management, environmental services and infrastructure.

• Municipal associations (associações de municípios): voluntary groupings of municipalities organised under private law, typically without delegated public authority. These associations focus on advocacy, technical co-operation, capacity-building and regional development initiatives. While more flexible and easier to establish than consortia, they generally lack the ability to directly deliver public services or manage significant financial resources.

• Co-operation agreements and informal arrangements: municipalities may also collaborate through contracts, agreements or project-based partnerships, often supported by state or federal programmes. These arrangements are typically used for specific initiatives, shared services or joint applications for funding, but do not create a separate legal entity.

Overall, Brazil’s legal framework combines strong federal regulation – through the Public Consortia Law – with flexibility in the choice of co-operation forms. Public consortia have become the cornerstone of inter-municipal co-operation, offering a robust institutional model for service delivery and territorial governance, while complementary arrangements such as municipal associations and contractual co-operation provide additional adaptability depending on local needs and capacities.

Bulgaria

Inter-municipal co-operation is enshrined in the 1991 Constitution (Article 137) and regulated by the Local Government and Local Administration Act (LGLAA) (Ministry of Regional Development and Public Work, 1991[9]). Chapter 8 of the LGLAA (articles 59-61) provides the legal basis for voluntary co-operation among municipalities for the implementation of tasks of common interest (as well as between the municipalities and districts). Amendments adopted in 2006 and 2017 further clarified and strengthened the regulatory framework for inter-municipal co-operation, providing municipalities with more precise legal instruments to establish co-operative arrangements.

According to LGLAA (Article 59), the objectives of municipal co-operation are to improve the quality of services of mutual interest, ensure more effective use of financial and administrative resources, optimise municipal costs and strengthen the municipality’s financial situation. Co-operation also aims to standardise and streamline work processes by realising economies of scale and division of labour, enhance financial control and transparency, and enable joint projects that address major regional and local challenges.

The LGLAA (Article 60) further states that municipal co-operation must be based on the principles of voluntariness, mutual interest, active choice, flexibility and dynamism, as well as transparency and accountability.

According to Article 61 of the LGLAA, co-operation agreements must specify one of the following forms of co-operation:

• Implementation of a specific project or activity: this includes joint delivery of services or infrastructure, possibly under a host municipality arrangement. It is based on a contract and does not create a new legal entity.

• Establishment of a non-profit legal person between municipalities: this creates a separate non-profit entity carrying out activities for public benefit

• Establishment of a profit-making legal person between municipalities. This covers municipal companies operating under private law, able to own assets, borrow, and engage in commercial activities.

• Implementation of a specific project or establishment of a legal person together with natural persons. This allows co-operation with private actors, either for a project or through co-ownership of a non-profit or commercial entity.

Art. 62 further clarifies that joint implementation may cover shared services such as IT management, financial accounting, HR, legal activities, construction/maintenance of technical (car parks, city transport, green areas, etc.) and social infrastructure (intended for healthcare, education, culture, sport, rest and tourism and social assistance.

Each co-operation agreement must specify the scope and objectives of the co-operation, the financial and property contributions of each party, as well as governance mechanisms.

Despite the fact that one of the guiding principles of inter-municipal co-operation in Bulgaria includes voluntary participation, there are mandatory forms of inter-municipal co-operation in two sectors, particularly in water supply, sewerage, and waste management, where joint service provision or membership in regional associations is required under the Water Act and the Waste Management Act (OECD, 2021[10]; CoE - Congress of Local and Regional Authorities, 2021[11]).

Overall, despite the existence of a legal framework, there is a limited uptake of inter-municipal co‑ordination. It is partly due to limited financial incentives, a non-integrated funding approach taken by line ministries and a local administrative culture that is non-conducive to collaboration (OECD, 2021[12]). While associations exist, they are primarily “trans-regional,” focusing on knowledge sharing based on common economic features rather than “functional” focusing on delivering public services or investments at the appropriate geographic scale (OECD, 2021[12]).

Canada

Inter-municipal co-operation in Canada is shaped by the country’s federal system, in which municipalities fall under exclusive provincial and territorial jurisdiction. There is no overarching federal framework for inter-municipal co-operation, co-operation mechanisms therefore differ significantly across provinces and territories. Municipal powers to collaborate - through agreements, shared-service arrangements, or joint governance bodies – are granted in provincial and territorial municipal legislation (OECD/UCLG, 2022[6]) (Spicer, 2015[13]). Although there is no overarching federal framework, the federal government supports collaboration indirectly through funding programs and policy initiatives that encourage regional planning, shared infrastructure, and co‑ordinated service delivery across municipal boundaries.

Inter-municipal co-operation takes several forms, from informal shared-service agreements to formalised joint governance bodies:

• Inter-municipal (inter-local) agreements are voluntary service-sharing agreements between neighbouring municipalities. They remain the most common and flexible co-operation instrument. Municipalities may jointly provide fire protection, transit, waste management, recreation services or water/wastewater systems.

• Multi-purpose regional or county structures: Some provinces have created structured supra-municipal tiers responsible for regional planning and shared services. For example, Ontario operates two-tier regions and counties, which deliver water, waste management, regional roads, transit and land-use planning for lower-tier municipalities. Quebec’s regional county municipalities (MRCs) - covering nearly the entire territory - are responsible for regional land-use planning, waste management and other shared services. MRCs represent one of the most institutionalised forms of inter-municipal co-operation in the country.

• Regional districts and regional service commissions. Several provinces have created metropolitan‑scale co‑operation bodies. For example, British Columbia has frameworks that have enabled co‑operative metropolitan governance arrangements in Greater Vancouver since 1967, on the basis of existing inter‑municipal special‑purpose bodies. Rebranded as Metro Vancouver in 2007, the Metro Vancouver Regional District comprises 21 municipalities, one electoral area, and one treaty First Nation. It is a multi‑purpose entity that plans for and delivers regional utility services, including drinking water, wastewater treatment, and solid‑waste management. It also regulates air quality, plans for urban growth, manages a regional parks system, provides affordable housing, and serves as a regional federation. New Brunswick operates 12 Regional Service Commissions, established under the Regional Service Delivery Act adopted in 2012 and significantly expanded following the province’s local governance reform implemented in 2023. The Commissions bring municipalities and rural districts together to co-ordinate and deliver regional services, including land use planning, solid waste management, and emergency measures planning, along with aspects of regional economic development. Since 2023, their mandate has been broadened to include additional shared services such as community development, tourism promotion, regional transportation, and regional facilities and infrastructure cost sharing (New Brunswick Canada, n/d[14]).

• Mandated collaboration frameworks: a major recent innovation is Alberta’s Intermunicipal Collaboration Frameworks (ICFs). Since 2018, all municipalities sharing a boundary must establish an ICF defining how they will plan, fund and deliver joint services - including water, wastewater, solid waste, emergency services and recreation. By 2020, 99% of Alberta municipalities had adopted an ICF (Government of Alberta, 2025[15]).

• Metropolitan-scale governance arrangements: Several provinces have created metropolitan-scale co-operation bodies. For example, British Columbia has provided frameworks to enable co‑operative metropolitan governance arrangements for Vancouver in 1967, on the basis of existing inter-municipal special-purpose bodies. Renamed Metro Vancouver in 2007, Metro Vancouver comprises 23 local authorities and is a multi-purpose entity that combines regulatory land use planning, infrastructure planning, drinking water, wastewater treatment, solid waste and housing (Horak M. and Doyon A., 2018[16]). Quebec has statutory metropolitan bodies: the Communauté métropolitaine de Montréal (CMM) and the Communauté métropolitaine de Québec. Both are mandatory supra-municipal governance bodies created by provincial law with responsibilities for metropolitan land-use planning, economic development, mobility, environmental management and housing. They are governed by councils composed of the mayors of all member municipalities with population-weighted voting.

Chile

The constitutional amendment of 2009, through Law 20.346, established that municipalities may voluntarily associate with one another, stating in Art. 118-6 of the Constitution that “the municipalities may associate between themselves in accordance with the relevant organic law, and may enjoy legal personality under private law”. They may also constitute or integrate private non-profit corporations or foundations whose object is the promotion and dissemination of art, culture and sport, or the promotion of communal and productive development works.” (Government of Chile, 2009[17]).

Subsequently, in 2011 the Chilean Congress promulgated Law 20.527, which amended the Ley 18.695 (the Organic Constitutional Law of Municipalities) and regulated the modalities of municipal associations. Under this law:

• two or more municipalities (whether in the same region or not) may form an “association of municipalities” (asociación de municipalidades) either via a formal convention without legal personality or via a private‐law entity with legal personality,

• the law provides that such associations may exist as a private‐law corporation, open to the municipalities’ pursuit of shared objectives (e.g. common services, municipal public works, management instruments, environmental/tourism/health programmes, capacity building).

Upon registration (via the “Registro Único de Asociaciones Municipales con Personalidad Jurídica de Derecho Privado” established by the Law No. 20.527 and managed by the Subsecretaría de Desarrollo Regional y Administrativo – SUBDERE -), such associations may hold patrimony, enter into contracts, receive contributions, grants, subsidies and other resources, and effect project operations

Associations are financed by membership fees intended to cover operational or administrative costs; they may also draw on donations, transfers from the national government and member municipalities, asset incomes and competitive public funds, but they remain limited. Despite this framework, the actual development of municipal associations in Chile remains limited (OECD/UCLG, 2022[6]; OECD, 2021[10]).

There were 79 associations registered in the official registry maintained by SUBDERE under the provisions of the Law No. 20.527 as of April 2026 (SUBDERE, 2026[18]). Despite the progress, integrated projects or investments conducted by municipalities associations remain limited so far, and the experiences vary greatly throughout the country (OECD, 2017[19]).

Colombia

Inter-municipal co-operation in Colombia is grounded in the Organic Law on Territorial Organisation - LOOT (Law 1454 of 2011), which recognises municipal associativity as a key mechanism to overcome fragmentation, strengthen service delivery and enhance planning capacity (Government of Colombia, 2011[20]). Colombia has 1 100 municipalities (many small, rural and fiscally weak), making inter-municipal co-operation crucial for pooling resources and operating at functional territorial scales (OECD, 2016[21]; OECD, 2019[22]; OECD, 2022[23]; OECD, 2022[24]; OECD, 2024[25]).

Colombia has three recognised forms of inter-municipal co-operation, which can be organised from least to most formalised: co-operation agreements, Associations of Municipalities, and Metropolitan Areas.

• Inter-administrative co-operation agreements (convenios interadministrativos): LOOT permits municipalities to establish co-operation agreements to carry out specific tasks without creating a new entity. These flexible arrangements are widely used for routine functions such as rural road maintenance, waste collection, equipment sharing or co-financed infrastructure.

• Associations of Municipalities (Asociaciones de Municipios - AMs): AMs are public-law entities (LOOT 2011, Arts. 10-12) enabling municipalities to jointly provide services, co‑ordinate planning and implement shared development projects. AMs have their own legal personality, assembly, governing board and executive director, and can receive delegated responsibilities from higher levels of government. AMs offer crucial benefits for small municipalities by providing economies of scale, increased service continuity and improved planning capacity. They have a growing role in environmental management, rural development, water and sanitation and administrative support (Pinzon & Moreno, 2023[26]). However, they face structural challenges: limited financial autonomy, weak technical staffing, dependence on voluntary contributions and insufficient clarity in mandates (López Marín, 2024[27]).

• Metropolitan Areas (Áreas Metropolitanas) have a constitutional basis and are regulated by Law 1625 of 2013 (Government of Colombia, 2013[28]). It is the most institutionalised form of inter-municipal co-operation. Metropolitan Areas are public territorial entities with political, administrative and fiscal autonomy, created voluntarily by a core city and neighbouring municipalities through a popular vote. They possess legal personality, a metropolitan board and director, and stable financing through mandatory municipal contributions and metropolitan surcharges. Metropolitan Areas must adopt a Metropolitan Development Plan and a Metropolitan Land-Use Plan (PEMOT) and manage key supra-municipal functions such as mobility integration, public transport, environmental regulation, air quality management and strategic land-use co-ordination. Six Metropolitan Areas exist, with the Metropolitan Area of Valle de Aburrá (Medellín) standing out as the most consolidated example, acting both as environmental authority and integrated transport manager (OECD, 2022[23]).

Although the legal inter-municipal framework has not changed, national policy has significantly strengthened inter-municipal co-operation. The National Development Plan 2022-2026 (Law 2294 of 2023 (DNP, 2023[29]) reinforces the National Registry of Associative Schemes (REAT) and ties national co-financing and technical assistance to participation in formal inter-municipal co-operation structures. In addition, the national government has expanded the role of Associations of Municipalities and Metropolitan Areas as cadastral managers, enhancing their fiscal capacity (OECD, 2024[25]).

Costa Rica

Inter-municipal co-operation in Costa Rica remains limited because the legal framework does not allow municipalities to create formal, public-law co-operation bodies to pool resources and provide services to a wider population. The Municipal Code (Law N.º 7794) defines municipal autonomy and responsibilities, but its only provision related to co-operation is Article 2, which authorises municipalities to “invest public funds jointly with other municipalities according to the conventions it signs” (Government of Costa Rica, 1998[30]). These co-operation agreements (convenios intermunicipales) are therefore the only legally existing inter-municipal arrangement, typically used on an ad hoc basis for shared services such as road maintenance, waste operations or minor infrastructure.

Existing co-operation therefore remains mostly informal or project-based, sometimes supported by the Instituto de Fomento y Asesoría Municipal (IFAM).

The only example of inter-municipal association is the Metropolitan Federation of Municipalities of San José, which promotes co-operation for spatial planning among the capital of San José and its nine neighbouring municipalities, but it lacks a metropolitan structure to co-ordinate the management of public urban services such as public transport and waste management (OECD, 2023[31]).

A major current development, however, is the Bill 24.080, which would create mancomunidades Municipales, as supra-municipal public entities with their own legal personality, allowing municipalities to jointly plan, manage services and execute territorial projects (National Assembly of Costa Rica, 2024[32]). If adopted, Costa Rica would gain its first formal inter-municipal co-operation mechanism, similar to associations of municipalities in other Latin American countries. However, there is a constitutional debate. The proposal has triggered intense constitutional scrutiny, with several concerns raised in expert opinions submitted to the Assembly (e.g. (University of Costa Rica, 2024[33]). There is a warning of possible unconstitutionality because the creation of supra-municipal bodies with decision making powers could be interpreted as limiting municipal autonomy (guaranteed under Article 169 of the Costa Rican Constitution), unless participation is fully voluntary and competences are clearly delimited. Additional concerns include unclear delegation of functions, risks to fiscal oversight if new entities manage independent budgets, and questions about the territorial logic and representativeness of groupings that may include non-contiguous municipalities.

Croatia

The Law on Local and Regional Self-Government, published in 2001 and revised several times, establishes the legal foundation for voluntary inter-municipal co-operation. Articles 54 and 54a allow municipalities and towns to jointly organise and perform tasks within their self-governing scope. The legal framework enables multiple forms of co-operation, ranging from informal arrangements and service contracts to fully institutionalised entities, and allows local government to co‑operate flexibly under public- or private-law arrangements, depending on the nature and scope of the shared task (Government of Croatia, 2001[34]). The relationships among participating units must be regulated by a formal agreement consistent with their statutes and relevant laws (OECD, 2024[35]; Council of Europe, 2024[36]).

Beyond information co-operation and joint initiatives, there are four main forms of co-operation:

• Contractual co-operation: formal service agreements between two or more local governments defining how a specific service or function will be jointly performed (e.g. waste collection, road maintenance). This is a widespread practice in Croatia.

• Shared administrative units / services: municipalities may create a joint office or administrative department for tasks such as accounting, spatial planning, or social welfare.

• Joint public-law institutions / bodies (zajednička javna ustanova): municipalities set up a distinct public-law body/institution to deliver a government function (e.g. fire brigades, cultural/social institutions). These bodies operate under public-law provisions and have their own governing structure, budget and staff.

• Joint companies (trading companies, d.o.o.): municipalities co-found a limited-liability company (often a utility) that provides services to all shareholders’ territories (e.g. water, waste). It has a separate legal personality, assets, and governance. It is the most institutionalised and most common in practice (OECD/UCLG, 2022[6]). For instance, the Waste Management Act enables local governments to establish a Waste Management Centre, for the purposes of jointly managing waste services. The scope and specific arrangements of the co‑operatives are defined through agreements between the participating local governments (LoGov, 2021[37]).

  Inter-municipal co-operation is supported by a financial incentive whereby local governments can obtain co-funding grants of up to 75% from the national government when they co-operate on administrative tasks (e.g. a joint administrative department or sharing the remuneration of a civil servant working for both municipalities). In addition, city and municipal administrations that co-operate to deliver a public service can also secure national co-funding grants of up to 25%. Both grants are available to cities and municipalities for up to five years after they enter into a co-operation agreement (OECD, 2024[35]).

Beyond incentives, inter-municipal co-operation is funded through contributions from the participating local governments, service fees, as well as from EU funds. Since 2022, the government has provided city and municipal governments with a wide range of financial (and non-financial) incentives to co-operate across jurisdictions, including specific grants (OECD, 2024[35]; Kurian, Swianiewicz and Teles, 2024[38]).

However, the most generous financial incentives are offered to cities and municipalities that choose to amalgamate with neighbouring local governments. In July 2022, the Government adopted a Decision on the criteria for granting aid to encourage voluntary functional or actual mergers of local self-government units. In September 2022, the Ministry of Finance issued a public call inviting local governments to express interest in receiving such support. The incentives include a one-time grant to repay the debt obligations of the local government being merged, coverage of merger-related costs, and capital and operational grants for a five-year period (Official Gazette of Croatia No 88/2022) (OECD, 2024[35]). Despite these measures, no municipal mergers have taken place to date, partly due to concerns about loss of political control.

Czechia

The legal framework for inter-municipal co-operation is primarily established under the Act on Municipalities (Act No. 128/2000 Coll.), which enables municipalities to join forces on matters of shared interest. Over time, a variety of co‑operative arrangements have emerged, ranging from informal service agreements to more institutionalised forms of collaboration such as Voluntary Associations of Municipalities (VAMs) and, more recently, the newly introduced Communities of Municipalities (Government of Czechia, 2000[39]).

• A basic form of inter-municipal co-operation occurs through public contracts, whereby one municipality provides services for another-an arrangement that particularly benefits smaller or lower-capacity municipalities. These contracts are commonly used in areas such as managing offences or providing child protection services (Sedmihradská, 2018[40]).

• However, municipalities most often prefer to collaborate through Voluntary Associations of Municipalities or VAMs (dobrovolné svazky obcí or DSO) (Sedmihradská, 2018[40]) (Bakoš et al., 2021[41]). A VAM is a legal entity under public law formed by two or more municipalities to promote their collective interests and exercise public tasks delegated by them, typically focusing on shared or sector-specific tasks. The founding agreement must be approved by the municipal councils of all participating municipalities. As of 2022, there were 702 registered VAMs across the country, though not all of them are active. VAMs are primarily established to perform autonomous competences, although the Administrative Code (Act No. 500/2004 Coll.) also allows them to carry out delegated competences (OECD, 2023[42]).

• Most VAMs are single-purpose entities, either created for one-time investment projects or for the ongoing provision of local services-most commonly waste management, sewerage and water supply. Other areas of co-operation include maintenance of public spaces, education, social care, health services, cultural and leisure activities, tourism development, and landscape management (OECD/UCLG, 2022[6]) (Mon1tor, 2024[43]). VAMs are typically financed through member contributions, non-tax revenues from their operations, and external resources such as central government grants and EU funds.

• In 2024, the Act on Municipalities (Act No. 128/2000 Coll.) was amended (Zákon 418/2023 Sb.) to introduce a new form of inter-municipal co-operation called the “Community of Municipalities” (Společenství obcí), aiming to strengthen co-operation, efficiency, and shared service delivery among small municipalities, thanks to a stronger legal and financial framework (Ministry of Interior of Czechia, 2025[44]). Effective since January 2024, the Community of Municipalities not only handles shared services but also focuses on co‑ordination and strategic development across the member municipalities, with shared municipal officers. It can also perform delegated state administrative tasks (Government of Czechia, 2023[45]).

• Unlike VAM, the creation of a Community of Municipalities is subject to specific conditions, including minimum size and territorial criteria. It may include municipalities located within the same administrative district and must comprise at least 15 members or three-fifths of all municipalities in that district. ach Community must adopt a development strategy, whose goals and priorities are binding for its members and must be approved by a majority of member mayors. Their revenues derive primarily from membership fees, user charges, and subsidies. Several existing VAMs are now in the process of being transformed into Communities of Municipalities (Tisnov, 2024[46]).

• A municipality may be a member of only one association. This condition does not limit the municipality's ability to participate in the activities of other voluntary associations of municipalities (e.g. existing single-purpose associations) or in other forms of inter-municipal co-operation.

• As of October 2025, a total of 730 municipalities (11.7% of all municipalities) co‑operate in 36 communities of municipalities, in which over 784 000 inhabitants (7.2% of the state's population) live on an area of 9 335 km² (11.8% of the state's area) (Ministry of Interior of Czechia, 2025[44]).

Denmark

Denmark’s legal basis for inter-municipal co-operation sits in the Act on Local Government (Kommunestyrelsesloven). The key rule is §60, which establishes the legal framework for municipalities to voluntarily collaborate on shared functions, with no limit on the areas of co-operation (Government of Denmark, 2019[47]). Under §60, if co-operation limits the powers of the participating municipal councils, it will require Danish Supervisory Authority for Municipalities and Regions of the Ministry of Interior (Ankestyrelsen) approval. (CoE - Congress of Local and Regional Authorities, 2022[48]).

The least formalised form of inter-municipal co-operation is delegation and co-operation by contract. Municipalities may delegate tasks to another municipality or co‑operate by agreement without setting up a separate body. These arrangements keep full control with the delegating councils and do not require Ankestyrelsen approval (and can typically be ended by the parties). They are common for day-to-day operational sharing (e.g. inspections, back-office functions) and are financed per the agreement.

Where an agreement curtails individual councils’ powers under the Act (e.g. one council takes binding decisions for several), the arrangement falls under §60 and must be approved by Ankestyrelsen, unless the co-operation qualifies for the §60a “small entity” exemption introduced in 2017. Approval focuses on legality and governance.

Municipalities can also co‑operate through inter-municipal enterprises (kommunale fællesskaber), with their own governing organ (a joint board). Once tasks are transferred to such body, responsibility for task execution lies with the joint organ rather than the individual councils. These inter-municipal enterprises operate under public law (can own assets, adopt budgets, contract, etc.) and are financed according to the founding agreement (population, use, cost shares). Ankestyrelsen’s approval is required.

Finally, municipalities also co‑operate through jointly owned companies (e.g. I/S partnerships or A/S limited companies) for utilities and commercial-type services (waste, water/energy, broadband, etc.). These are private-law entities, not §60 bodies, but must comply with municipal company and sectoral rules. Many utilities were corporatised by sector legislation. Governance and financing follow company law and shareholder agreements.

Overall, Denmark has extensive co-operation as, on average, each municipality participates in 47 co‑operative arrangements with other municipalities or private companies across employment, education/day-care, social services, environment/technical services, elderly care, health, digitisation and more (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities, 2022[48]). However, to reap economy of scale and scope, recent recommendations emphasise strengthening inter-municipal co‑operation in a more systematic and evidence-based way, moving beyond predominantly voluntary and uneven arrangements. The (OECD, 2024[49]) specifically highlights the potential to improve efficiency by expanding existing inter-municipal partnership arrangements for service delivery to additional policy areas, alongside better use of benchmarking and performance comparison.

Estonia

The constitutional basis for municipal co-operation is found in §159 of the Constitution of the Republic of Estonia which explicitly grants municipalities the right “to form associations and joint agencies with other municipalities.” The main statutory framework is the Local Government Organisation Act (LGOA). Under § 12 and § 62-63, municipalities are empowered to form associations and joint agencies with one another. Under LGOA § 62(1)(2): “rural municipalities and cities may … grant authority to another rural municipality or city for this purpose” (i.e. for joint functions) and “may found joint agencies on the basis of a contract” (Government of Estonia, 2014[50]).

The Administrative Reform Act conducted in 2016 aimed to strengthen local governance capacity and resulted in a structural municipal reform (municipal mergers) and the abolition of the county governments. It also prompted the strengthening of instruments fostering inter-municipal co-operation.

Initially, Estonian legislation allowed municipalities to establish joint agencies, a broad and flexible category covering various co‑operative arrangements such as shared service units, jointly owned companies or foundations, and informal administrative co-operation. However, these structures often lacked a clear legal status, uniform governance rules and the capacity to perform public tasks, limiting their effectiveness and accountability.

The 2017 Administrative Reform introduced a new and more formalised model: the joint administrative agency (JAA). These bodies are established under public law and enable municipalities to jointly perform statutory administrative functions, such as social services, education administration, spatial planning or permit issuing. JAA have their own budgets and staff, operates as part of the public administration system, and may exercise public authority on behalf of participating municipalities. Their legal status provides clearer rules for governance, financing and supervision, strengthening administrative capacity, particularly for smaller municipalities that retained their autonomy after the merger process. As such, joint administrative agencies represent a key institutional innovation of the reform, offering a more robust and accountable framework for inter-municipal co-operation in Estonia (Ministry of Finance of the Republic of Estonia, 2019[51]).

In practice, inter-municipal co-operation in Estonia remains limited. One key reason is that Estonian municipalities rely heavily on central government transfers, which weakens financial incentives for municipalities to collaborate voluntarily. Following the 2017 Administrative Reform, some co-operative structures were maintained at the county level, particularly for public transport and spatial planning (OECD, 2025[52]).

In addition, with the termination of county governments in 2018, several regional tasks previously performed by the state were transferred to municipalities. To support this shift, the regulation of regional associations of local authorities was revised and strengthened, allowing existing county associations to merge and form joint associations covering two or more counties. Municipalities may organise these new responsibilities, such as county development planning, regional public transport, health promotion, security councils and cultural co-operation, through a regional association, by assigning them to one municipality under a co-operation agreement, or by establishing another co-operation body, such as a joint administrative agency. Regional associations therefore remain primarily co‑ordination and representation structures, but they can now also serve as platforms for delivering certain regional functions where municipalities choose to do so (Ministry of Finance of the Republic of Estonia, 2021[53]).

Inter-municipal co-operation is funded by both the state and municipalities, with additional support from EU grants. Overall, Estonia’s institutional architecture provides for inter-municipal co-operation, but increasing the scale, depth and density of such co-operation remains an ongoing policy challenge (OECD/UCLG, 2022[6]; OECD, 2022[54]; OECD, 2025[55]; CoE - Congress of Local and Regional Authorities,, 2023[56]; Chebarova M. & Eerma D., 2025[57]).

Finland

Finland has a long tradition of inter-municipal co-operation, which is governed by the Municipal Act (410/2015) (Government of Finland, 2015[58]). The Act provides a comprehensive framework for the establishment, organisation, financing, and governance of co-operation between municipalities. Co‑operation is widespread across nearly all service areas, reflecting Finland’s relatively small average municipal size and extensive service responsibilities. There are 3 main forms, ranging from the least formalised to the most:

• The most flexible form of inter-municipal co-operation is contract-based collaboration, where municipalities agree - without establishing a separate legal entity - to jointly provide services or perform administrative tasks. This form of co-operation is regulated under the Municipal Act and may take the form of service agreements, partnership contracts, or administrative delegation. Contractual arrangements are common in water supply, building inspection, consumer and debt counselling, and certain educational and welfare support services. These agreements are governed by private or public law, depending on their content and financing, and are often used by smaller municipalities seeking efficiency without long-term institutional commitments.

• Municipalities may also establish or co-own joint municipal companies (JMCs), typically organised under private law as limited liability companies. These entities are widely used in housing, energy, water and sewerage, waste management, and administrative support services, allowing municipalities to pool resources and operate within a market-oriented framework. Joint companies may also involve private partners when permitted by law (OECD, 2024[59]).

• The most institutionalised form of inter-municipal co-operation is the joint municipal authority (JMAs) (kuntayhtymä), a public-law entity established by two or more municipalities to perform statutory duties jointly, such as healthcare (until 2023), education, and regional planning. Joint municipal authorities possess legal personality, their own budgets, and governing bodies. They are responsible for providing public services on behalf of their member municipalities. JMAs make strategic decisions and oversee service delivery. They are financed through municipal contributions, service fees, and state grants.

While most joint municipal authorities are voluntary, some are compulsory: municipalities are required to form regional councils (maakuntaliitto) for regional development and spatial planning. Each of Finland’s 19 regional councils functions as a joint municipal authority. Until 2022, joint municipal authorities also played a major role in hospitals, social and health care, but these responsibilities were transferred to the newly established well-being services counties as part of Finland’s health and social care reform. (OECD, 2024[59]). Municipalities may also participate in associations or foundations governed by private law to promote shared objectives in areas such as cultural services, regional development, or tourism promotion. These entities operate under the Associations Act and Foundations Act, and while they have legal personality, they are less binding than statutory joint authorities.

Financing for inter-municipal co-operation typically comes from member municipalities, which contribute based on agreed-upon formulas (e.g. population, service use, or tax revenue). Some entities also receive state transfers or service-based revenues. Decision making powers are defined in founding agreements, and representatives from member municipalities sit on the governing boards of joint authorities or companies (CoE - Congress of Local and Regional Authorities,, 2024[60]; OECD/UCLG, 2022[6]).

France

Municipal co-operation has a long-standing history in France, with a strong legal framework and continuous reforms. The right of self-administration is stipulated under Article 72 of the Constitution, under which is derived the right of municipalities to associate. Articles L5210 to L5224-1 of the 1996 General Code of Local Government (Code général des collectivités territoriales, CGCT) (Government of France, 1996[61]) outline the general rules for inter-municipal co-operation integrating subsequent laws.

Initially, co-operation took the form of single-purpose (SIVU) and multi-purpose (SIVOM) syndicates created first by the law of March 1890 to deliver shared services such as water, waste, or transport (they still exist, although their number has declined steadily). (DGCL, 2025[62]).

In the 1990s, reforms introduced new inter-municipal entities (Law 92-125 related to territorial administration of the Republic): the EPCI (Établissements Publics de Coopération Intercommunale) with taxation powers. They are public law entities that enable municipalities to collaborate on local services and for integrated territorial development. A municipality can belong to only one EPCI. They have legal and financial autonomy and have their own taxation powers. The Chevènement Law of 1999 (Law 99-586 related to the strengthening and simplification of inter-municipal co-operation) streamlined and strengthened these structures, making fiscal and territorial integration a national priority.

Law 2004-809 on local freedoms and responsibilities strengthened decentralisation in France by transferring key competencies and resources from the State to regions, departments, and EPCI, and expanded their financial and administrative autonomy. It also improved the coherence and functioning of EPCI by facilitating their mergers and transformations, clarifying shared competences, and refining fiscal arrangements between municipalities and inter-communal structures.

A subsequent Local Government Reform Law in 2010 (2010-1563) further streamlined and strengthened EPCI by promoting their consolidation through mandatory coverage of all communes by an inter-municipal structure, simplifying governance, and enhancing their fiscal and strategic co‑ordination powers.

The MAPTAM law (2014-58) further consolidated this system by creating the metropolis status for large urban areas (see below) and reinforcing urban-rural linkages. Article 79 of MAPTAM law created a new form of public-law entity called Pôle d’équilibre territorial et rural (PETR) to organise co-operation between several EPCI, especially involving rural areas and small/medium towns. They are typically established as syndicats mixtes fermés (closed mixed unions) composed of several EPCI to carry a “projet de territoire” (territorial project) common to all members. They thus function as function as supra-inter-municipal co‑operative structures.

The 2015 NOTRe Law set up a minimum threshold for inter-municipal groupings to ensure more efficient co-operation (15 000 inhabitants). All municipalities must be part of an EPCI. Subsequent laws, such as Law 2022-217 related to decentralisation, deconcentration and simplification (called 3DS) include measures related to inter-municipal co-operation.

Today, there are four categories of EPCI covering the entire territory (see the main text for more details):

• 22 metropolises, which are metropolitan areas of at least 400 000 inhabitants in an urban area of over 650 000 inhabitants.

• 14 “urban communities” (communautés urbaines) accounting between 250 000 and 400 000 inhabitants:

• 230 “agglomeration communities” (communautés d’agglomération), formed around one or more urban centres with at least 50 000 inhabitants, including a core commune of at least 15 000.

• 989 “communities of municipalities” (communautés de communes), the latter mainly located in rural areas. A “communauté de communes” requires a minimum population of around 15 000 inhabitants (or lower in sparsely populated areas).

Since the MAPTAM Law, 22 metropolis have enhanced competences (economic development, innovation, energy transition, and urban policy), fiscal powers, and institutional recognition. Among them, Paris, Lyon and the Métropole d’Aix-Marseille-Provence, the largest French metropolitan areas, have an ad hoc metropolitan status with different governance structures - i.e. different organisation, responsibilities and resources, reflecting an asymmetrical approach. The Métropole du Grand Lyon, operational since January 2015, has (unlike Paris and Aix-Marseille Provence) a particular metropolitan status: it merged the responsibilities of the existing intermunicipal co-operation entity Grand Lyon and those of the département du Rhône, covering about 1.3 million people - the only one of its kind in France.

Overall, the four categories EPCI with own-source taxation exercise obligatory competences transferred from municipalities by law and optional responsibilities. The biggest changes came from Loi NOTRe (2015-17), which expanded the mandatory list, and the Loi 3DS (2022), which introduced “transferts à la carte”. A last law on 11 April 2025 removed the mandatory transfer of water and sanitation for Communautés de communes.

Finally, EPCI can create or join local public companies under private law in the form of Sociétés publiques locales (SPL) and Sociétés d’économie mixte locales (SEML). SPLs are companies with at least two shareholders (public local authorities or their groupings) which must act within the inter-municipal competences. SEMLs allow local authorities and their groupings to create a company in which they associate with private shareholders and possibly other public actors, to carry out operations in fields like urban development, housing and infrastructure.

The financing of EPCI is a mix of municipal contributions, local taxes, state subsidies, EU funds, and service revenues, depending on the type of municipal co-operation (General Code of Local Self-Government (CGCT). Regarding state subsidies, EPCIs receive a general grant (dotation globale de fonctionnement des EPCI), which comprises an inter-municipal grant and a compensation grant. (OECD/UCLG, 2022[6]) (Congress of Local and Regional Authorities, 2024[63])

Germany

The Federal Constitutional Court has recognised the right of local governments to co‑operate. (Federal Constitutional Court, 2014[64]). Each Land establishes its own rules and legal forms for inter-municipal co-operation, which typically take the form of public-law entities or contractual agreements for shared service provision. Germany’s co‑operative federal tradition, rooted in the constitutional principles of Bundestreue (federal loyalty) and the pursuit of “equivalent living conditions” (gleichwertige Lebensverhältnisse), provides a favourable context for such horizontal collaboration (Behnke N., 2025[65]).

Inter-municipal co-operation (interkommunale Zusammenarbeit, IKZ) is a longstanding and widespread feature of German local governance. German Länder have developed a rich set of legal instruments that allow municipalities to co-operate while preserving their autonomy. Despite variations across states, several core models exist nationwide.

These forms range from loose, voluntary collaboration (like working communities - Arbeitsgemeinschaften) to highly institutionalised joint bodies with legal personality and substantial operational capacity. Among the formal co-operation arrangements, we find:

• Public-law co-operation agreements (öffentlich-rechtliche Vereinbarungen), through which one municipality performs specific tasks on behalf of another, based on a contractual allocation of responsibilities and financing. These agreements are commonly used for back-office functions or limited service tasks and do not require the establishment of a new entity.

• Joint administrative bodies (such as Verwaltungsgemeinschaften, Verwaltungsverbände, Samtgemeinden or Verbandsgemeinden, depending on Länder) for municipalities requiring deeper administrative co-operation. These structures involve a shared administrative office that performs compulsory tasks for member municipalities while political authority remains at the municipal level. They help small municipalities fulfil statutory obligations and professionalise service delivery.

• The more institutionalised form is the special-purpose association (Zweckverband). This is the most widespread form of inter-municipal co-operation in Germany. Zweckverbände are public-law entities with their own legal personality, assets, staff and decision making bodies. They are commonly responsible for technical and infrastructure services such as water and wastewater management, waste disposal, public transport or hospital provision, and can levy fees or charges for their activities.

• Municipalities may also establish municipal companies (gemeinsame Kommunalunternehmen, GmbH or AG), operating under public or private law. These entities possess significant organisational and financial autonomy, may enter markets, borrow funds and manage major service infrastructures. They represent the most corporatised form of co-operation and are frequently used in sectors such as energy, housing or transport.

For instance, Bavaria’s Law on Communal Co-operation (Kommunale Zusammenarbeitsgesetz, KommZG) provides the overarching legal framework for these forms. Zweckverbände are particularly widespread as single- or limited-purpose public-law associations delivering essential local services such as waste management, water supply, wastewater treatment, and regional transport. In Saxony, these associations are used extensively for shared tasks while preserving municipal autonomy, for example, in water supply, spatial planning, registry services, and local development.

Beyond formal associations, co-operation may also take the form of supra-local assistance (überörtliche Hilfe), where one municipality provides services to another under a contractual arrangement, common in areas such as emergency services or local public transport (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities, 2022[66]; Behnke N., 2025[65]).

Finally, since the 1990s, the traditional bottom-up approach to inter-municipal co-operation has been complemented by broader national frameworks promoting territorial co-operation at the metropolitan level. The federal government has supported co-operation among major urban regions through the recognition of eleven “European Metropolitan Regions” (Europäische Metropolregionen) (OECD, 2019[67]) which encourage voluntary partnerships between municipalities, districts, and Länder across administrative boundaries. These regions cover a large part of Germany’s territory but differ considerably in the degree of institutionalisation and integration achieved (Horak M. and Doyon A., 2018[16]).

Greece

Article 102 of the Greek Constitution provides for the creation of compulsory or voluntary associations of local governments to execute works or render services when provided by law (not a direct constitutional right). The Municipalities and Communities Code (Article 245 of Law 3463/2006) establishes that voluntary horizontal co-operation between municipalities may be achieved through the creation of municipal associations (Syndesmoi), which are legal entities governed by private law (Government of Greece, 2006[68]; Angelidis, 2025[69]). Municipalities may also establish co-operation frameworks governed by private law for specific projects or services.

The Kallikratis reform (Law 3852/2010) introduced a more comprehensive and formalised framework for inter-municipal and inter-regional co-operation, expanding both voluntary and obligatory mechanisms. Mandatory inter-municipal co-operation, known as “administrative support”, was designed to enable small municipalities to perform newly devolved functions, such as town planning, technical services, and social welfare, by receiving administrative and technical assistance from neighbouring municipalities or associations (CoE - Congress of Regional and Local Authorities, 2015[70]). The reform also institutionalised Programming Agreements (Programmatikes Symfonies) and Inter-municipal or Inter-level Co-operation Agreements, enabling municipalities and regions to jointly plan, finance, or implement projects (Angelidis, 2025[69]).

Inter-municipal entities in Greece take several forms:

• Municipal Associations (Syndesmoi): private-law legal entities for joint service delivery or project implementation.

• Municipal Enterprises and Inter-Municipal Development Agencies: private-law entities, typically organised as development companies (single-share or joint-stock), focusing on local economic development, spatial planning, infrastructure and social services. A prominent example is the Thessaloniki Development Agency (ANATOLIKI S.A.), which operates as an inter-municipal development company supporting multiple municipalities in areas such as urban regeneration, social inclusion and housing. It has been involved in EU-funded initiatives on social housing and vulnerable groups, illustrating how such agencies can combine inter-municipal co-operation with project-based financing and technical expertise.

• Inter-municipal Co-operation Networks (IMCNs): flexible co-operation schemes, introduced by Kallikratis, allowing municipalities or regions with shared characteristics to form non-profit civil companies to address issues such as waste management, water services, or sustainable development (Angelidis, 2025[69]). For instance, seven island municipalities formed an inter-municipal co-operation network to collaborate on maritime transport, technical capacity, and environmental management (Council of Europe, 2018[71]).

The scope of inter-municipal co-operation has progressively broadened, covering a wide range of responsibilities, including social welfare, environmental management, water supply and sanitation, emergency response, and economic development. Despite this diverse framework, many inter-municipal entities remain inactive or underused, due in part to limited administrative capacity and resource disparities between municipalities (Angelidis, 2025[69]; OECD, 2020[72]).

Finally, the recently adopted Law 5013/2023 on Multilevel Governance further clarifies roles and responsibilities among levels of government, reinforcing the legal and financial framework for horizontal and vertical co‑ordination. Inter-municipal co-operation is primarily financed through the contributions of the participating municipalities' budgets and other contributions as outlined in the contract, allowing flexibility to include additional funding sources, such as national grants (OECD/UCLG, 2022[6]; CoE - Congress of Regional and Local Authorities, 2015[70]; Angelidis, 2025[69]; Ministry of Interior Greece, 2024[73])

Hungary

Hungary’s Fundamental Law (Article 31) guarantees municipalities the right to manage their affairs and to co‑operate with other local authorities. The framework for inter-municipal co-operation combines voluntary and compulsory mechanisms.

Voluntary co-operation is regulated by the Act CXXXV of 1997 of the Associations and Co-operation of Local Governments (1997), which enables municipalities to form inter-municipal associations with legal personality (önkormányzati társulások) to perform shared tasks, represent joint interests or pursue collective development initiatives. These associations may, in turn, establish public-law organisations, non-profit bodies or companies to carry out delegated functions (Kovacs, 2018[74]).

The Cardinal Act CLXXXIX of 2011 on Local Governments further refines the system. Article 85 requires municipalities with fewer than 2 000 inhabitants to form joint municipal offices (közös önkormányzati hivatalok) to carry out administrative, financial and technical duties; this provision affects more than four-fifths of Hungarian municipalities. Article 87 permits municipal councils to form inter-municipal associations for the joint discharge of tasks when efficiency or service quality can be improved (Government of Hungary, 2011[75]).

By 2021, there were 1 517 inter-municipal associations and 738 joint municipal offices, covering 82.6% of municipalities, highlighting the scale of co-operation in a system characterised by many small local governments. Financing for co-operation structures is shared between the state – via annual budget allocations according to task volume – and member municipalities, as specified in the co-operation agreements.

Inter-municipal co-operation operates in sectors such as waste management, education, social services, utilities and regional development. However, following the 2013 territorial reform, many competences were recentralised to state-run district offices (járási hivatalok), which reduced municipal autonomy and somewhat diminished the incentives for voluntary co-operation. Nonetheless, inter-municipal co-operation remains an important instrument to enhance service efficiency and administrative capacity in Hungary’s fragmented local government landscape (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities,, 2021[76]).

Iceland

While the Constitution (Article 78) guarantees the autonomy of municipalities, the Local Authorities Act (No. 138/2011) explicitly grants them the right to co‑operate, delegate responsibilities, and form joint institutions” under Chapter IX (Government of Iceland, 2011[77]). Co-operation in Iceland is voluntary and flexible and has become essential for smaller municipalities to deliver services effectively. Many smaller municipalities (some with fewer than 1 000 inhabitants) rely heavily on inter-municipal co-operation to meet statutory obligations (Magnússon M. Á. S., 2025[78]). The National Plan for Municipal Affairs 2019-33 therefore prioritises strengthening local capacity through co-operation and encouraging voluntary amalgamations to reduce fragmentation and improve service efficiency.

Iceland’s co-operation framework spans a continuum from ad hoc contractual co-operation to fully institutionalised joint entities:

• Contract-based co-operation (most flexible): under Article 92, municipalities may conclude bilateral or multilateral agreements to execute specific administrative or technical tasks without entailing delegation of powers.

• Co-owned companies (byggðasamlög): these formalised inter-municipal companies represent a more institutionalised form of co-operation. They are independent legal companies jointly owned by two or more municipalities, established to provide shared services in areas such as fire and rescue, water distribution, waste management, social services, and education. Their operation is subject to the Administrative Procedures Act (No. 37/1993) to ensure accountability and due process. Each participating municipality finances the company in proportion to its use or by formula agreed upon in the founding charter (Article 94). A 2010 state-municipal agreement introduced a minimum population threshold of 8 000 inhabitants for the provision of services for persons with disabilities, which further stimulated the formation of byggðasamlög.

• Regional partnerships (landshlutasamtök): Iceland’s eight regional associations of municipalities serve as territorial co‑ordination platforms for strategic planning, regional development, and advocacy. They facilitate co-operation among local governments within each region and act as intermediaries between municipalities and the central government. Such co-operation is subject to approval from the relevant Ministry to enter into effect (Article 93).

Article 94 stipulates that municipalities are financially responsible for the co-owned companies they participate in. For other co-operation agreements, the financing arrangements must be explicitly defined in the contract between the participating municipalities (CoE - Congress of Local and Regional Authorities,, 2017[79]).

In practice, inter-municipal co-operation is mostly single-purpose with many territorially overlapping schemes. The main tasks that are shared by municipalities are projects in the field of welfare and education. However, there are also large municipal co-operative organisations in the capital area (Council of Europe, 2024[80]). The Regional Association of Municipalities in the Capital Area (SSH) oversees several highly institutionalised byggðasamlög, including SORPA (waste management), Strætó bs. (public transport), and the Capital Fire and Rescue Service, which operates as public-law entities delivering shared metropolitan services (Magnússon M. Á. S., 2025[78]).

Ireland

Ireland’s framework for inter-municipal co-operation is primarily set out in the Local Government Act 2001 (Government of Ireland, 2001[81]) and its subsequent amendments. The Act enables local authorities to collaborate on the joint provision of public services, share administrative functions, and co‑ordinate regional policies.

The least formalised form of co-operation is contractual and shared-services co-operation. Under Sections 85-86 of the 2001 Act, local authorities may enter into agreements to jointly perform or manage any of their functions without creating a new legal entity. Each authority retains its statutory powers but agrees by contract to share staff, systems, or resources.

Since 2012, this form of co-operation has expanded through Ireland’s Local Government Shared Services model, co‑ordinated by the Local Government Management Agency (LGMA) and overseen by the Department of Housing, Local Government and Heritage (DHLGH). Shared-service centres under lead-authority models now provide joint payroll management (MyPay), human resources, building control, waste enforcement, treasury management, ICT, and procurement (Local Government Management Agency, 2024[82]). These co‑operative arrangements represent the most prevalent and operationally significant form of inter-municipal co-operation in Ireland (Congress of Local and Regional Authorities, 2023[83]).

The second way to co‑operate are joint committees. Section 52 of the 2001 Act permits two or more local authorities to establish a joint committee to perform specific tasks, deliver shared services, or advise the participating councils, operating within the public-law framework. Such committees are created by mutual agreement but require the consent of the Minister for Housing, Local Government and Heritage if they are to act as independent legal entities (able to hold funds, enter contracts, or employ staff). The Minister may also direct local authorities to form a joint committee where necessary for efficient service delivery or policy co‑ordination-for instance, in waste-management planning regions, fire and emergency services, or river-basin management.

At a higher level of institutionalisation, there is another form of co-operation through the three Regional Assemblies created by the Local Government Reform Act 2014. These assemblies group Ireland’s 31 local authorities (merged from 114 local authorities in 2014) into Eastern and Midland, Northern and Western, and Southern regions. They are statutory public-law bodies tasked with co‑ordinating regional spatial and economic strategies, managing EU structural funds, and ensuring consistency between national and local development plans. Although they are not voluntary associations, the assemblies serve as Ireland’s platform for horizontal co‑ordination among local governments and for vertical co-operation with national departments and agencies, but they cannot be considered as inter-municipal bodies per se.

The financing of inter-municipal co-operation is detailed in each collaborative agreement, typically using cost-sharing formulas based on population, service use, or budget capacity. Shared-services projects receive oversight or co-funding from the DHLGH and the LGMA. Joint committees and Regional Assemblies are funded through statutory local-authority contributions and state grants.

Collaboration among local governments through shared-services and regional planning mechanisms has become an essential component of effective multi-level governance. However, Ireland’s system could benefit from stronger horizontal co‑ordination to implement national spatial and investment priorities (OECD, 2023[84]).

The financing is usually detailed in the collaborative agreements between municipalities, often with guidance or approval from the central government or relevant ministerial departments. Ireland has implemented a shared services programme in several areas, including waste management, payroll functions, building control, treasury management, and procurement through contractual arrangements

Israel

Inter-municipal co-operation in Israel has evolved from functional co-operation under state supervision (cities’ unions) to voluntary, multi-purpose regional clusters (eshkolot). These arrangements have become an important mechanism for overcoming municipal fragmentation and improving local service delivery in a highly centralised governance system.

• The first form of municipal co-operation was established under the Cities and Local Councils Unions Law (1955), which remains in force. The Cities’ Unions (Igudey Arim) are public-law entities created to enable neighbouring municipalities to jointly manage essential infrastructure and public services, particularly in water supply, sewage treatment, waste management, fire and rescue services, and occasionally education or cemeteries. There are currently 29 Cities’ Unions operating across Israel (OECD, 2025[85]). Each union is governed by a council of mayors and municipal representatives, under the supervision of the Ministry of the Interior. They are financed primarily by mandatory contributions from member municipalities and earmarked state grants.

• A second and more flexible form of inter-municipal multi-purpose co-operation emerged in the late 2000s under the form of regional clusters or Eshkolot. The Western Galilee Eshkol, created in 2009, marked the beginning of voluntary, bottom-up regional co-operation among municipalities. A pilot programme launched in 2012 by the Ministry of the Interior, Ministry of Finance, and several civil society organisations supported the creation of additional clusters.

To formalise their status, the City Unions Law was amended in 2016 to legally recognise Eshkolot as regional clusters with public-law status. The amendment authorised delegation of powers, exemptions from public tendering, and eligibility for regional development funding. The Eshkolot were declared national priority entities, enabling direct funding from line ministries. By 2023, Israel had 12 Eshkolot, encompassing around 170 local authorities (65% of all municipalities) and 3.4 million residents. Each Eshkol must include at least six localities, with a combined population exceeding 50 000 and diverse socio-economic and demographic profiles. Governance is exercised by an assembly of mayors and senior officials, supported by thematic committees and professional staff. Participation in projects remains voluntary.

Funding comes from a mix of state transfers, member contributions, and project-based support from line ministries and donors. The Ministry of the Interior allocates transfers according to socio-economic level and peripherality. The clusters operate in social services, education, environmental protection, waste management, digitalisation, and procurement.

Despite clear progress, Eshkolot face significant challenges. They operate under heterogeneous structures, with uneven participation and limited statutory authority. Stronger municipalities sometimes resist regional co‑ordination, while weaker ones struggle to finance participation. Co-operation with national ministries also varies, with some – such as the Ministry of Environmental Protection – actively supporting clusters, while others lack formal engagement mechanisms.

A comprehensive national strategy for inter-municipal co-operation is under development. The Ministry of the Interior has begun evaluating the Eshkolot’s role in regional development, including potential future functions in spatial planning and economic development. Together, the Cities’ Unions and Eshkolot now form a dual system of inter-municipal co-operation in Israel – one focused on technical service delivery, the other on regional collaboration and development – reflecting the gradual shift from centralised, functional co-operation to decentralised, multi-purpose governance (OECD/UCLG, 2022[6]; Uster A. & Beeri I., 2025[86]; OECD, 2021[87]; OECD, 2025[88]).

Italy

Inter-municipal co-operation in Italy is primarily regulated by the Consolidated Law on Local Authorities (Legislative Decree 267/2000 – TUEL (Government of Italy, 2000[89])), which consolidates previous legislation, including Law 142/1990. The TUEL provides three main forms of inter-municipal co-operation, with varying degrees of institutionalisation: conventions, consortia () and unions of municipalities (unioni di comuni).

• Conventions (convenzioni - Article 30) are the most flexible and least formalised form. They are contractual agreements through which two or more municipalities delegate or jointly manage specific functions or services, without creating a new legal entity. They are widely used for administrative tasks, shared staff, procurement, or single-service delivery, and allow municipalities to co‑operate while maintaining full institutional autonomy.

• Consortia (consorzi - Article 31) are legally recognised public entities established by municipalities to jointly manage specific public services or infrastructure, with their own statutes, financial autonomy and organisational structure. Historically common in sectors such as water, waste management or social services, consortia represent a more institutionalised form of co-operation. However, recent reforms, particularly since the 2010s, have sought to reduce their number and integrate their functions into unions of municipalities, leading to a gradual phase-out of this model.

• Unions of municipalities (unioni di comuni - article 32) constitute the most structured form of inter-municipal co-operation. They are public-law bodies with their own governing bodies, staff and budgets, enabling municipalities, particularly smaller ones, to jointly manage a broad set of functions in a stable and integrated manner. Unions can assume compulsory functions from member municipalities and are increasingly promoted by national and regional governments as the preferred mechanism to strengthen administrative capacity and ensure efficient service delivery where municipal mergers are politically difficult. Recent legislation has made unions eligible for financial incentives and additional competences, positioning them as a key alternative to amalgamation in fragmented areas.

  Alongside these forms, Italy also has mountain communities (Comunità montane) and their successors, Unioni montane, which group municipalities in mountainous areas to manage territorial development, environmental protection and service provision in challenging geographic contexts. Although regulated under separate legislation, they function as specialised unions with territorial mandates and play a significant role in service co‑ordination in alpine and Apennine regions.

Subsequent laws strengthened this framework (Law 122/2010, Law 135/2012, Law 56/2014) (Puntillo, 2017[90]). The Law No. 56 of 7 April 2014 – "Provisions on Metropolitan Cities, Provinces, Unions and Mergers of Municipalities" (Delrio law) in particular (Government of Italy, 2014[91]) strengthened unioni di comuni as the main framework for inter-municipal co-operation among small municipalities, particularly those with fewer than 5 000 inhabitants (and less than 3 000  inhabitants in mountain areas) for which co-operation is now mandatory to exercise certain “fundamental responsibilities” (abolished in 2024 see below). It required joint management of core administrative and service functions, introduced clear governance structures (president, council, and assembly), and offered financial incentives to encourage participation. The reform aimed to improve efficiency, service quality, and administrative capacity across Italy’s fragmented municipal landscape.

Responsibilities of unions of municipalities mainly involve public service provision and competences in urban management (town planning, environment), local road networks, culture and recreation, and social welfare. Funding of municipal co-operations is mostly done through contributions from participating municipalities and state and regional funding in the case of Unions of Municipalities (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities,, 2024[92]).

The Delrio law also abolished the provinces as self-governing entities, and transformed them into inter-municipal co-operation bodies, which also became “metropolitan cities” in each of the 14 metropolitan areas designated by the law (Rome, Turin, Milan, Venice, Genoa, Bologna, Florence, Bari, Naples and Reggio Calabria - and four additional cities in special regions - Palermo, Messina and Catania in Sicily, as well as Cagliari in Sardinia). They are designed to handle strategic functions such as strategic planning for the entire metropolitan area, metropolitan-scale transport, land-use, infrastructure, economic development, environment, and sometimes higher education and innovation. They also manage services previously handled by the provinces (e.g. roads, schools, and environmental protection). The governance structure of the 14 metropolitan cities is defined uniformly by the Delrio Law (including a metropolitan mayor, a metropolitan council and a metropolitan conference), although some local variations exist in practice e.g. for Roma, Naples and Reggio Calabria (OECD, 2025[93]).

Finally, the new Decree-Law of 27 December 2024 No. 202 (“Milleproroghe 2025”) introduced new reforms: it abolished the obligation for small municipalities to manage fundamental functions jointly. From 2025 onward, municipalities under 5 000 inhabitants are no longer legally forced to participate in inter-municipal co-operation to provide these functions.

Japan

Inter-municipal co-operation in Japan is governed by a comprehensive and flexible legal framework centred on the Local Autonomy Act 1947 (Government of Japan, 2025[94]) which defines several mechanisms through which municipalities can jointly plan, deliver and finance public services. The Act provides multiple pathways for co-operation along a continuum of institutionalisation, ranging from simple agreements to fully fledged wide-area administrative associations.

• At the least formalised end of the spectrum, Article 252-2 of the Local Autonomy Act enables municipalities to conclude co-operation agreements for co‑ordinating specific administrative tasks or service delivery. These agreements do not create a new entity and are commonly used for back-office operations, facility management or small-scale social services.

• In addition, Article 252-14 authorises municipalities to delegate specific responsibilities to one another through mutual agreements, enabling more efficient allocation of administrative functions.

• Slightly more structured are inter-municipal councils established under Article 252-2-2, which allow municipalities to deliberate and plan jointly on matters of shared interest, such as disaster-response co‑ordination or regional development planning, though they hold no executive authority.

• More institutionalised arrangements include the joint establishment of public facilities or shared service institutions under Article 252-7, which may involve shared staffing, pooled budgets and dedicated management structures. These entities typically manage welfare facilities, regional sewerage assets or crematoriums.

• At the most formalised end of the spectrum, Japan recognises wide-area administrative associations (kōiki rengō) and special-purpose district governments (ichibu jimu kumiai), both of which are also explicitly established under the Local Autonomy Act as public-law entities with their own legal personality. Special-purpose district governments (Articles 284 to 291 allow municipalities to jointly manage clearly defined “partial affairs” through an autonomous public entity with its own governing board, administrative capacity and independent budget. Wide-area administrative associations (Articles 291-2 to 293) constitute a higher-level joint authority with broader delegated powers, their own councils, administrative staff, financial autonomy and by-law making capacity. In practice, wide-area associations typically oversee specialised healthcare and welfare facilities, while special-purpose district governments most often manage fire and emergency services, ambulance, waste management, waste-to-energy facilities, water supply and sewerage, crematoriums (Kimura, 2020[95]).

According to recent research, more than 70% of inter-municipal co-operation in Japan takes the form of delegated or contracted services, while roughly 15% involves these more formalised joint (Noda, 2023[96]).

These co-operation mechanisms are increasingly important as many municipalities face demographic decline, fiscal pressures and administrative capacity constraints (OECD, 2016[97]). Recent evidence shows that both horizontal trust among municipalities and vertical support from higher levels of government are key drivers of effective co-operation in Japan. National and prefectural financial incentives are key to influence the uptake of more formal institutional arrangements (Noda, 2023[96]).

Inter-municipal co-operation is also more and more supported by sector-specific legislation. For example, the Act on Revitalisation and Rehabilitation of Local Public Transport Systems (2007) encourages municipalities to jointly plan and reorganise local transport networks, by enabling shared mobility planning committees and multi-municipality transport strategies.

Korea

Inter-municipal co-operation in Korea is framed by the Local Autonomy Act (LAA), which provides several legal instruments for local governments to work together on shared tasks (Government of Korea, 2021[98]). The Act, updated through major reforms in 2021, is the core statute governing local autonomy, the distribution of responsibilities and the creation of joint bodies among local governments.

In a context of rapid population ageing, strong metropolitan concentration and shrinking rural regions co-operation between local governments is increasingly necessary to sustain service provision and regional development, fostering urban-rural co-operation (OECD, 2021[99]; OECD, 2025[100]; OECD, 2022[101])

The Local Autonomy Act offers a continuum of co-operation mechanisms, from soft co‑ordination to fully fledged joint public bodies:

• Administrative consultative councils (Section 2, Articles 169-175) are the least formalised instrument. They allow two or more local governments to organise a consultative council to jointly handle part of their affairs. Councils have internal rules approved by each participating council, a chair and members, and can request information and mediate disputes, but they do not have a separate legal personality. They are widely used for policy dialogue and co‑ordination.

• Local government associations (Article 176 and related provisions) are a more formal form of inter-municipal co-operation. They are public-law entities with their own legal rights and obligations (juridical persons) created by agreement between local governments and subject to approval by the Minister of the Interior and Safety. Associations can manage development funds, issue local bonds, and perform joint affairs such as regional development, infrastructure financing or other shared functions.

• Special-purpose local governments / special joint bodies (Article 199 and related provisions) are the most institutionalised inter-municipal structures. They are established for the joint performance of part of the affairs involving two or more local governments and have their own governing body and administration. Recent legislation, such as the Special Act on Support for Depopulation of Local Areas (2022) explicitly encourages the formation of these special-purpose local governments, administrative consultative councils and local government associations to improve living conditions and manage services in shrinking regions (Government of Korea, 2022[102]).

Inter-municipal co-operation is particularly important in sectors where economies of scale and cross-boundary spillovers are strong, such as waste management, local transport, water and sewerage, emergency services, and some welfare and development functions.

At the metropolitan level, metropolitan-scale inter-municipal co-operation is achieved through consultative councils, specific joint committees / specialised public bodies for metropolitan services established under the Local Autonomy Act and national sectoral laws. Co-operation is thus mainly functional, especially in transport (Metropolitan Transport Committee, like in Seoul (OECD - International Transport Forum, 2018[103])), planning, environmental management, waste, water and emergency services. There is no metropolitan tier of government based on formal inter-municipal co-operation. Metropolitan cities (e.g. Busan, Daegu, Gwangju, Daejeon, Ulsan, Incheon) are single-tier local governments with the same legal rank as a province, created by national legislation, and not by co-operation among multiple municipalities.

Latvia

Latvia's local governance system was profoundly modified with the 2021 administrative-territorial reform, which merged 119 municipalities into 43 larger and more capable units. Despite this reform, inter-municipal co-operation remains an important topic to co‑ordinate service delivery, regional development, and representation as Latvia has no elected regional tier.

The Law on Local Government adopted in 2022 and in force since 1 January 2023, modernised the previous 1994 framework and clarified municipalities' right to co‑operate, providing a clear, graduated framework for co-operation (Government of Latvia, 2022[104]). According to Section 78 of the Local Government Law, local governments may co-operate through a broad range of instruments with varying degrees of formalisation and legal status:

• Co-operation agreements (sadarbības līgums): Under general public administration law, any public entity (including municipalities) may conclude a co-operation agreement for tasks within its competence. Such agreements require a municipal council decision and typically define the objectives, each party’s contributions (financial and in-kind), and governance arrangements (e.g. a joint council).

• Joint institutions (kopīgas iestādes): Regulated by Section 80 and complemented by the Law on Public Administration, these represent the most institutionalised form of inter-municipal co‑operation. Municipalities may establish a joint institution by mutual agreement, governed by an approved charter defining governance, financing, and accountability arrangements. Created to deliver shared public services, these institutions have their own legal personality and an independent budget.

• Joint commissions (kopīgas komisijas): Regulated by Section 81, these are semi-formal co-operative bodies without independent legal personality. They enable municipalities to co-ordinate policies or operations in specific areas such as emergency management, spatial planning, or public procurement. Their establishment and functioning must be formalised through co-operation agreements and by-laws approved by the participating councils (Latvian Association of Local and Regional Governments, 2026[105]).

In practice, co-operation tends to focus on services like education, transport or utilities, where economies of scale matter. For example, co-operation in cultural events, school transport and water services is already common. By institutionalising diverse forms of co-operation, Latvia’s 2022 Local Government Law reinforces the capacity of municipalities to jointly address common challenges and deliver services more efficiently in the post-reform territorial landscape (Reinholde I. Stučka M. & Auliciema I., 2025[106]; CoE - Congress of Local and Regional Authorities,, 2024[107]).

In addition to these municipal co-operative bodies, Latvia has established five planning regions operate as co‑ordination and development bodies under the Law on Regional Development (2002), but they lack political self-government. In addition, municipalities can also act collectively in pursuit of shared objectives - such as advocacy, capacity building, or participation in EU-funded projects “joint associations” or foundations, which are private-law entities regulated by Section 78 and the Law on Associations and Foundations.

Lithuania

The Law on Local Self-Government provides a basic legal foundation for co-operation between municipalities (Government of Lithuania, 2017[108]). Under Article 5 of the LLSG, three forms of inter-municipal co-operation exist:

• Joint agreements: municipalities can jointly agree to achieve common objectives.

• Joint procurement agreements: municipalities can conclude joint procurement agreements to purchase services from non-municipal providers.

• Delegated agreements: municipalities can delegate the implementation of specific public services to another municipality through contractual arrangements.

These provisions are limited to contract-based co-operation and do not define the establishment of joint entities or shared governance structures. In practice, as noted by (OECD, 2024[59]), inter-municipal co-operation takes broader and more diverse forms than those foreseen in the LLSG. Co-operation typically occurs through inter-municipal agreements, joint service organisations or bodies, and, in some cases, jointly owned municipal companies. These arrangements are permitted under sectoral or general legislation – such as the Law on Public Administration or the Law on Local Government Enterprises.

Recent reforms have improved the institutional environment for inter-municipal co-operation in Lithuania. The Law on Regional Development (2020) created ten Regional Development Councils (RDCs) as legal entities uniting municipalities within each region to co‑ordinate regional development planning, investment programming and alignment with national priorities (OECD, 2023[109]). Although RDCs provide a new platform for horizontal co‑ordination, their mandate remains strategic rather than operational, and they do not directly manage shared services. Broader policy frameworks, such as the White Paper on Regional Policy 2017-2030 (National Regional Development Council, 2017[110]), the Integrated Territory Development Programme and the National Progress Plan 2021-2030 (Government of Lithuania, 2020[111]) also recognise inter-municipal co-operation as a lever for more efficient service delivery and reduced territorial disparities, but practical mechanisms for shared service provision remain limited.

In addition, a pilot carried out in the Tauragė+ functional zone, bringing together the municipalities of Tauragė, Jurbarkas, Pagėgiai and Šilalė, aimed to test a practical model for shared municipal service provision. The exercise focused on primary healthcare (PHC) and long-term care (LTC), two services facing significant pressure due to demographic decline, staff shortages, fragmented responsibilities and unequal physical access to care across the area (OECD, 2024[59]).

Luxembourg

Inter-municipal co-operation in Luxembourg is grounded in the Communal Law of 13 December 1988 (Loi du 13 décembre 1988 relative à l’organisation des communes (Government of Luxembourg, 1988[112]), which authorises communes to establish three formal mechanisms of co-operation. There are three main forms of co-operation, from the least to the most formalised:

• Intercommunal agreements (conventions intercommunales): they are flexible, ad hoc contracts allowing communes to co‑ordinate on specific tasks - such as shared facilities, small infrastructure projects or temporary administrative co-operation - without creating a legal entity.

• Intercommunal syndicates (syndicats intercommunaux): by far the most important and widely used, syndicates form the backbone of service delivery co-operation in the country. They consist of a separate public-law entity through which two or more municipalities jointly deliver services, manage infrastructure and share costs. Each syndicate has its own governing committee of municipal delegates and an executive board headed by a president. As of 2024, Luxembourg has 61 intercommunal syndicates, and most communes belong to 7 to 9 syndicates, reflecting the small size of municipalities and the need to pool capacity.

• Communal associations (associations de communes) are the most integrated form of co‑operation, but also the least utilised. Designed to prepare communes for potential municipal mergers, they allow municipalities to jointly manage certain functions during a transition period. Their relevance has diminished as Luxembourg increasingly uses targeted merger incentives and legislation rather than preparatory association structures.

Overall, Syndicates and agreements are a relatively efficient way to ensure municipal services and equal quality and access to them. However, many single-purpose syndicates exist, and there is fragmentation that generates duplication of overhead for the same responsibilities, which is a potential inefficiency driver (Banque Centrale du Luxembourg, 2012[113]).

At the metropolitan level, although functional intercommunal syndicates such as Agglo-Centre, PRO-SUD and Nordstad enable municipalities to pool resources for shared services, Luxembourg has no single metropolitan authority at the scale of the wider metropolitan area.

Mexico

Inter-municipal co-operation in Mexico is grounded in a strong constitutional and legal architecture that combines federal framework legislation with detailed state-level rules.

The central legal basis is Article 115 of the Constitución Política de los Estados Unidos Mexicanos, which grants municipalities autonomy and explicitly authorises them to co‑ordinate and associate with one another, with their state, and with the federation for the joint exercise of functions and provision of public services. Article 115 requires each state to regulate the modalities of this co-operation through its own legislation.

At the state level, inter-municipal co-operation is operationalised through municipal Organic Laws (Ley Orgánica Municipal), which define municipal powers and specify the legal instruments through which municipalities may interact, co‑operate, and engage in projects that cross municipal boundaries, including the financing mechanisms. In practice, inter-municipal co-operation takes forms with varying degrees of institutionalisation, ranging from flexible contractual arrangements to fully institutionalised entities.

• A first category consists of inter-municipal co-operation agreements (convenios de coordinación o colaboración). These are formal but non-institutionalised arrangements that do not create a new legal entity. They can be established either for specific tasks or short-term service provision, or for multiple tasks over several years. They are used most notably for public security, road maintenance, basic environmental projects, and public transport corridors – sectors where there are strong co-ordination needs, particularly in metropolitan and peri-urban areas (OECD, 2015[114])

• A stronger and more institutionalised form of co-operation takes place through inter-municipal associations (asociaciones intermunicipales or mancomunidades). These are formal public-law entities with legal personality, their own budget and governing board. Because they provide stable, long-term management capacity, they are primarily used in sectors that require continuous operation, specialised staff and shared infrastructure, such as water supply and sanitation, solid-waste treatment, environmental and natural-resource management, and, in some cases, regional economic development (OECD/UCLG, 2022[6]; Depetris-Chauvin, Durante and Gutierrez, 2024[115]).

These institutionalised forms of co‑ordination remain, however unevenly implemented across states and sectors, with only a small number of consolidated multi-municipal bodies in place (Maravalle Caldera Sánchez and González Pandiella, 2024[116]).

For metropolitan areas, the General Law on Human Settlements, Land-Use Planning and Urban Development (LGAHOTDU ) provides the federal framework for metropolitan and territorial co‑ordination (Government of Mexico, 2016[117]). As a ley general, it establishes national principles, minimum standards, and the distribution of responsibilities across levels of government, and obliges states to harmonise their legislation accordingly. LGAHOTDU mandates the creation or strengthening of metropolitan governance bodies and provides the overarching structure within which municipalities and states co‑ordinate on urban development and metropolitan governance, leaving state laws to determine the concrete procedures, legal forms, governance arrangements and financial rules for inter-municipal co-operation. Despite this progress, governance fragmentation continues to challenge effective implementation across Mexico’s diverse regions (OECD, 2019[118]).

Building on the LGAHOTDU framework, metropolitan co‑ordination bodies bring together municipalities and state governments to plan and manage land use, mobility and infrastructure across metropolitan zones. Their powers vary across states and many remain advisory, but they represent an important institutionalised platform for vertical and horizontal co‑ordination within metropolitan areas. The most advanced form of inter-municipal co-operation is found in metropolitan planning institutes (IMEPLAN/IMPLAN), technically specialised, permanent institutions charged with producing metropolitan development plans, generating strategic data and guiding investment and planning decisions. Their institutional continuity and technical mandate make them one of the most consolidated forms of inter-municipal co-operation in the country (Maravalle Caldera Sánchez and González Pandiella, 2024[116]).

A relevant ongoing development is the Preliminary Draft Metropolitan Constitutional Reform, prepared by SEDATU between 2022 and 2023. This work informed a reform initiative proposing amendments to Articles 4, 73, 115 and 116 of the Constitution, aimed at strengthening metropolitan governance and inter-municipal co-operation (OECD, 2023[119]). The initiative was presented to the Chamber of Deputies on 15 November 2022 and remains under examination by the Commission of Constitutional Points and the Commission of Metropolitan Zones. As of mid-2025, no decree has been enacted.

Netherlands

The Municipal Act (Gemeentewet) enables municipalities to co‑operate with other municipalities (Government of Netherlands, 1992[120]) and is complemented by the Joint Regulations Act (Wet Gemeenschappelijke Regelingen or WGR Act), first adopted in 1984, updated in 2015 and recently in 2022. All public forms of co-operation between municipalities are collectively called “joint regulations”. The 2015 WGR amendment was introduced to improve the democratic legitimacy and governance clarity of joint arrangements. The 2022 reform enhanced the flexibility and transparency of inter-municipal co-operation, enabling municipalities to collaborate by policy domain and better align with regional and national strategies. Although broadly applicable, it primarily benefits metropolitan areas such as MRDH (Rotterdam-The Hague), MRA (Amsterdam Metropolitan Area), Eindhoven Metropolitan Region, strengthening co‑ordinated governance for housing, mobility, and climate action.

This WGR allows municipalities, but also provinces and water boards, to co‑operate voluntarily to deliver shared services or co‑ordinate strategic planning and establish joint entities. The Act provides a general framework for shared services provision, but municipalities have the freedom to determine their organisation and operations through agreements (OECD, 2024[59]). The WGR allows for a spectrum of co-operation from light co‑ordination to fully institutionalised public bodies.

• The simplest form is the “Centre municipality” model (centrumgemeente model), where one core municipality delivers services for neighbouring ones (Utrech for example).

• This can evolve into a joint board (gemeenschappelijk bestuur) or a policy region (beleidsregio), where municipalities co‑ordinate specific policies without creating a new legal entity, for example Metropoolregio Amsterdam (MRA) and Regio Utrecht.

• More formal co-operation occurs through a common arrangement (gemeenschappelijke regeling). The main purpose is to establish a framework agreement defining shared competences (e.g. waste management, regional safety). It can serve as a legal foundation for more formal co‑operation, and result in the creation of a public body.

• An institutionalised inter-municipal co-operation form is the operational management entity: it has a legal personality and a single-tier board. It is used by municipalities to jointly carry out operational or implementation tasks (e.g. shared services, waste management, IT), offering a lighter governance structure than a full public body.

• The most fully institutionalised inter-municipal co-operation body is the “public body” (openbaar lichaam), which has its own legal personality, staff, and budget. These formal entities - such as MRDH (Rotterdam-The Hague), Regio Twente, Metropoolregio Eindhoven - hold delegated powers and provide the most integrated and strategic form of inter-municipal co-operation in the Dutch system. They mainly operate in service areas that require scale, professional expertise and cross-municipal co‑ordination. Their core responsibilities include shared administrative and back-office functions (such as ICT, HR and legal services), social and healthcare provision, economic development and spatial planning, tax collection and property valuation, as well as environmental regulation and waste management. Public bodies also play a key role in safety and emergency management, including crisis co‑ordination and disaster response (Veenendaal, 2023[121]).

Inter-municipal co-operation is done on a voluntary basis in general, but if one or more municipalities request it and if necessary for a compelling public interest, a provincial executive may oblige municipalities to co‑operate (Government of Netherlands, 1992[120]). Inter-municipal co-operation is financed through contributions from participating municipalities and the State, which is further regulated by other acts, such as the Financial Relations Act (CoE - Congress of Local and Regional Authorities,, 2021[122]) (Government of the Netherlands, 2014[123]).

New Zealand

Inter-municipal co-operation in New Zealand operates within a flexible and pragmatic legislative framework centred on the Local Government Act 2002 (LGA 2002). Adopted after the series of reforms that significantly restructured local governments through amalgamations, greater corporatisation and privatisation (OECD, 2017[124]), the LGA broadened and redefined local government’s powers and roles and responsibilities. It grants local authorities a general power of competence (Section 12) and requires them to act in ways that promote collaboration (Section 14). These provisions allow councils to enter co‑operative arrangements unless explicitly prohibited (Government of New Zealand, 2002[125]; The New Zealand Productivity Commission, 2013[126]).

In 2014, the LGA 2002 was amended again in line with the “Better Local Government New Zealand” reform. This new amendment aimed, among others, encourage intermunicipal co-operation and shared services. More recently, the Future for Local Government Review (2021-2023) has highlighted the need for stronger collaboration and shared capacity among councils to address fiscal pressures and deliver complex regional functions (Department of Internal Affairs, 2023[127]).

Beyond informal and contractual co-operation arrangements under Section 12, co-operation ranges from joint services to fully corporatised joint entities:

• Joint service arrangements and administrative sharing (Section 14): councils may jointly appoint officers, share chief executives, or pool administrative units. These arrangements remain organisational rather than institutional but allow for operational integration and cost-sharing in areas such as environmental health, inspection, compliance, and customer services.

• Joint committees: Under Schedule 7, Section 30(1)(b) of the LGA 2002, two or more councils may establish joint committees with delegated statutory powers. Joint committees are widely used for regional planning, regulatory services, shared service oversight, natural-resource and environmental management. They offer a formal governance structure while maintaining councils’ autonomy.

• Council-Controlled Organisations (CCOs): defined in Parts 5-6 of the LGA 2002, a CCO is any company, trust or partnership in which one or more local authorities hold at least 50% of voting rights or appoint a majority of the directors. CCOs have separate legal personality, independent governance boards and dedicated budgets. CCOs deliver major infrastructure and utilities such as transport, water, and cultural facilities. CCOs enable large-scale asset management and specialised service delivery. For example, the Tauranga Council is involved with other councils in several CCOs to deliver shared services and joint procurement (Tauranga Council, 2020[128]).

Beyond the LGA, sectoral legislation establishes mandatory regional co-operation bodies, but it goes beyond inter-municipal co-operation. For example, the Land Transport Management Act 2003 requires the creation of Regional Transport Committees, bringing together territorial and regional authorities for joint transport planning (Crawford, Ron; Shafie, Hamed, 2019[129]).

Norway

While the Constitution (Articles 49 and 49a) guarantees the principle of local self-government, it does not provide a constitutional basis for inter-municipal co-operation. Instead, co-operation is regulated entirely by statutory law.

A major reform was introduced with the adoption of the Local Government Act (Law No. 83/2018), which fundamentally restructured and clarified the legal framework for inter-municipal co-operation. The Act established a coherent spectrum of co-operation models, ranging from informal arrangements to highly institutionalised entities, and replaced earlier, less standardised forms (Government of Norway, 2018[130]). Together with the Inter-Municipal Companies Act (Law No. 6/1999), this framework defines the conditions under which municipalities may collaborate to perform public functions, deliver services, or co-ordinate regional policies (Government of Norway, 1999[131]).

Inter-municipal co-operation can be understood as a continuum from least to most formalised arrangements, depending on the degree of statutory regulation, governance structure, and legal autonomy:

• Contractual and other “legally permitted” co-operation: At the least formalised end, municipalities may co-operate through agreements, networks, or other legally permitted arrangements. These forms are flexible and typically used for co-ordination, joint projects, or knowledge sharing. They do not create a separate legal entity and are governed primarily by contract law. Such inter-municipal co-operation cannot exercise public authority.

• Host-municipality co-operation (Section 20-2) (vertskommunesamarbeid): This statutory model allows one municipality to perform delegated tasks on behalf of others. It does not create a separate legal entity, but is governed by detailed legal provisions and formal agreements. It is the primary mechanism for delegating authority to make individual decisions in areas such as child welfare, health services, or building regulation. The municipality, which delegates authority to a host municipality, retains legal and financial responsibility.

• Inter-municipal political council (Section 18-1) (interkommunalt politisk råd): This form provides a formal structure for political co-ordination across municipalities. It consists of elected representatives and may constitute a separate legal entity if specified in the co-operation agreement. However, it has no independent decision making power regarding service delivery and serves primarily as a forum for strategic and policy co‑ordination.

• Municipal task community (Section 19-1) (kommunalt oppgavefellesskap): This is a more structured arrangement for the joint performance of administrative or technical tasks. It may be established as a separate legal entity and includes formal governance bodies and financial rules. Participating municipalities share unlimited financial liability for their obligations. It is commonly used for shared services such as ICT, administration, planning, and technical operations.

• Inter-municipal companies (interkommunale selskaper, IKS): municipalities (and counties) may establish inter-municipal companies under the Inter-Municipal Companies Act (1999). These are separate legal entities governed by detailed statutory rules, with representative assemblies and boards. They are widely used for capital-intensive or technical services such as water supply, waste management, fire and rescue, and cultural institutions.

• Private-law entities (e.g. limited liability companies – AS, co-operatives): municipalities may co-operate through private-law entities governed by company or co-operative law. These structures provide limited liability and are typically used for market-oriented or commercial activities, such as energy production, transport services, or cultural enterprises (Norwegian Ministry of Local Government, 2013[132]).

Given Norway’s low population density, extensive territory and many small municipalities, inter-municipal co-operation has become a key mechanism for efficient service delivery and effective local governance (Schakel Solvang & Stein, 2025[133]). It is extensive and deeply embedded: every municipality participates in at least one co‑operative arrangement, and most in several. Co-operation is most prevalent in utility sectors - such as power supply, water and sewerage, waste management and public transport - but also in auditing, emergency services, educational-psychological counselling and child welfare (Arntsen, Torjesen and Karlsen, 2021[134]). (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities,, 2024[135]). These arrangements are typically financed through member contributions defined in formal agreements or, in the case of host-municipality co-operation, through financial settlements between participating municipalities.

Overall, inter-municipal co-operation in Norway is firmly grounded in statutory law and since the 2018 reform, the framework has become more structured, transparent, and diversified, providing municipalities and counties with a flexible set of instruments to share resources, co-ordinate service delivery, and address cross-boundary challenges. In a country characterised by sparse population, long distances, and a strong tradition of local self-government, inter-municipal co-operation is an essential component of effective and sustainable local governance.

Peru

Inter-municipal co-operation has a clear constitutional foundation. Article 194 of the Constitution of Peru (1993, amended) states that “Municipalities may associate among themselves or form co‑operative agreements for the execution of works and the provision of services (Congress of the Republic, 1993[136]). The main legal instrument governing inter-municipal co-operation is Law No. 29029 - Ley de la Mancomunidad Municipal (2007), which creates the mancomunidad municipal as a public entity with legal personality and administrative autonomy (Government of Peru, 2007[137]). Additional procedural rules are set by the Presidencia del Consejo de Ministros, which maintains the national registry of mancomunidades and oversees compliance (Presidencia del Consejo de Ministro, 2020[138]).

Mancomunidades are formed through a legal agreement between two or more municipalities or regions to jointly provide services or undertake construction projects. This instrument is meant to enhance the efficiency and reach of public services and infrastructure development. However, as of September 2024, there are 213 registered mancomunidades at the municipal level, although only 25 are currently operational (OECD, 2025[139]). The limited functionality of many mancomunidades is due to legislative constraints that prevent them from managing their own budgets. As a result, member municipalities must agree on transferring funds to a single municipality designated to deliver the joint services, which places a disproportionate burden on one municipality, hindering effective operation (Official Gazette Law No. 29029, 2007[140]; PCM, 2024[141]).

In 2022, the Government adopted a Programme for the development of inter-municipal associations (PAMM) to strengthen Peru’s inter-municipal associations. The reform responds to limited service articulation, weak institutional capacity and declining administrative performance. The PAMM aims to reinforce institutional foundations, update the legal framework and build a stronger identity for inter-municipal co-operation. It provides technical assistance, capacity-building, and support for digital transformation, transparency and citizen participation. The Programme also standardises tools for joint planning and service delivery, promoting more effective co‑ordination of policies and investments across municipal boundaries. Overall, it seeks to transform mancomunidades into operational actors of territorial development and strengthen Peru’s decentralisation agenda (Secretario de Descentralización, 2022[142]).

Regional mancomunidades were created in 2011 (PCM, 2015). In contrast to their mushrooming municipal counterparts, co-operation among regions is developing rather slowly in Peru and there are not many success stories. To date, the regions of Apurímac-Ayacucho-Huancavelica joined efforts in 2013, as did the regions of Qhapaq Ñan Nor Amazónico in the same year (OECD, 2016[143]).

Poland

The Constitution of Poland guarantees local governments the right to co‑operate. Article 172(1) states that “Units of local government shall have the right to associate.” This constitutional provision underpins a wide range of inter-municipal co-operation mechanisms, subsequently developed through ordinary legislation.

The main legal framework is provided by the Act on Municipal Self-Government of 8 March 1990 (Government of Poland, 1990[144]), complemented by provisions in the Act on County Self-Government and the Act on Voivodeship Self-Government Over the past three decades, these laws have enabled municipalities to jointly deliver services, manage infrastructure and co‑ordinate territorial development [note: the Law on Associations also allows municipalities to create associations of municipalities (stowarzyszenie gmin), governed by private law. However, these associations are primarily oriented towards co-ordination, representation, advocacy and joint initiatives rather than the joint provision of public services]. The Act on Municipal Self-Government establishes several forms of co-operation that vary in legal status, degree of formalisation and scope of autonomy.

• The least formalised are inter-municipal agreements (porozumienia międzygminne, Article 74). These are contractual arrangements under which one municipality performs specific public tasks on behalf of another. No new entity is created. Such co-operation enables municipalities to delegate functions - commonly in public transport, education, fire protection, or administrative services - while maintaining their separate legal and financial autonomy.

• At a higher level of institutionalisation, municipalities may form inter-municipal unions (związki międzygminne, Articles 64-73). These are public-law entities with legal personality, created by at least two municipalities to jointly carry out specific public tasks. They are managed by an assembly of representatives from member municipalities and an executive board, and may own property, employ staff, adopt budgets and take binding decisions. Inter-municipal unions are widely used for water supply, waste management, public transport, environmental protection and spatial planning. In 2023, there were around 200 such unions in operation, involving between 2 and 49 municipalities (Mirska A., 2025[145]; CoE - Congress of Local and Regional Authorities,, 2019[146]; OECD/UCLG, 2022[6]).

• Municipalities may also co‑operate through inter-municipal companies (spółki międzygminne) regulated by the Act on Municipal Economy. These are joint commercial entities, owned by local governments but governed by private law. They are commonly used for activities such as waste management, energy generation, district heating and local transport, where cost sharing and technical expertise are critical.

• Shared service centres (Centra Usług Wspólnych, CUW): introduced through the Amendment to the Act on Municipal Self-Government of 25 June 2015 (Dz.U. 2015 poz. 1045, in force since 2016 (Government of Poland, 2015[147])), CUWs allow municipalities to provide shared administrative, financial and organisational services to their subordinate units or partner municipalities. CUWs can operate under inter-municipal agreements or within inter-municipal unions, serving as shared back-office hubs for accounting, payroll, HR or procurement. They are particularly important for rural and small municipalities, where limited administrative capacity makes such pooling arrangements efficient and cost-saving (Łukaszczyk Z., 2018[148]; PAP Local Government Service, 2019[149]).

At the metropolitan scale, Poland adopted a general Act on Metropolitan Unions in 2015, but it was never implemented nationally. a general framework for metropolitan co-operation was introduced through the Act on Metropolitan Unions in 2015. Municipalities and counties were allowed to form public-law “metropolitan unions” to manage shared urban functions. However, this act was never implemented nationally. Instead, the Act on the Metropolitan Union in the Silesian Voivodeship (2017) created the Upper Silesian-Zagłębie Metropolis (Górnośląsko-Zagłębiowska Metropolia), the only functioning metropolitan union in the country, covering 14 local governments in the Silesian region with strong functional linkages and at least two million inhabitants. It has legal personality, its own budget, and carries out joint tasks such as transport co‑ordination, spatial planning, and regional promotion. To date, no similar legal framework exists for other Polish metropolitan areas. No comparable legal framework currently exists for other metropolitan areas (OECD, 2022[150]; OECD, 2021[151]).

Beyond these instruments, Poland has made extensive use of EU-supported territorial co-operation tools, notably Integrated Territorial Investments (ITIs) and Local Action Groups (LAGs) under the LEADER/Community-Led Local Development (CLDD) approach. These mechanisms have significantly strengthened horizontal and vertical co-operation among municipalities, particularly within functional urban areas and rural regions (Mirska A., 2025[145]).

Overall, Poland’s system of inter-municipal co-operation combines a constitutionally protected right of association with a detailed statutory framework offering multiple pathways-from simple contractual agreements to fully institutionalised public-law unions. EU cohesion-policy instruments have further reinforced these co‑operative structures, supporting more integrated and multi-level territorial governance.

Portugal

Article 253 of the Constitution states that municipalities may form associations and federations to administer common interests. The national government has long facilitated inter-municipal co-operation. Laws 10/2003 and 11/2003 allowed municipalities to form joint entities for both general and specific purposes, such as delivering water and sanitation infrastructure. These evolved into the current Inter-municipal Communities (Comunidades Intermunicipais or CIMs), formalised under Laws 45/2008 and 75/2013 (Government of Portugal, 2013[152]), the latter being updated by the Law 24-A/2022 (which amends the legal framework for local authorities, expanding on the regime for metropolitan areas and intermunicipal communities). Geographically, the CIMs follow the boundaries of the NUTS 3 regions, i.e. 21 intermunicipal communities. While membership in an CIM is not compulsory, all municipalities are currently members, as municipalities are steered to join by upper-level incentives associated with the management of European Union (EU) structural funds. The CIMs are governed by the intermunicipal assembly (deliberative power), the intermunicipal council, the executive secretariat (executive power) and the Strategic Council for Intermunicipal Development (advisory power). They can take on the functions and tasks assigned by law to the municipalities. However, CIMs can only provide services that are assigned to them by municipalities and the central government. CIMs (along with municipalities and parishes) have been involved in the transfer of competences from the state (e.g. education, transport) under Law 50/2018 and other complementary legislation (OECD, 2020[153]).

CIMs provide a legal framework for municipalities to collaborate in strategic areas where pooling resources can generate economies of scale and improve service delivery. Municipalities may delegate certain tasks to a CIM, and CIMs may enter into multi-level contracts with the central government or participate in frameworks for shared responsibilities. Their competences typically include regional and sub-regional planning and development, co‑ordination across municipalities of public services (such as transport, mobility, waste management and water/sanitation), and engagement with central administration in domains such as education, vocational training networks and infrastructure. However, their authority remains dependent on the willingness of member municipalities and on sufficient financial and administrative capacity. While CIMs give municipalities useful co-ordination tools and support urban-rural linkages, they were created through a top-down approach and remain limited in policymaking autonomy (OECD, 2025[154]).

In addition, national legislation (1991, 2003, 2008, 2013) defines the framework for the Lisbon and Porto Metropolitan Areas, both organised as inter-municipal co-operative arrangements. Funded through municipal contributions and state transfers, they focus on transport, spatial planning, regional development, waste management, and water and sanitation. The Lisbon MA (18 municipalities) and Porto MA (17 municipalities) are governed by assemblies composed of delegates from member municipalities. While they can “participate”, “promote” and “co‑ordinate” metropolitan-scale policies, their authority remains limited and largely dependent on municipal and central government support (OECD, 2020[153]).

Romania

The legal foundations for inter-municipal co-operation in Romania are set out in several key acts. The overall system of local self-government is defined by the Administrative Code (Government Emergency Ordinance No. 57/2019, as amended by Law No. 387/2023) and the Law on Local Public Finances (Law No. 273/2006). Sectoral legislation complements these, including Law No. 51/2006 on the management and joint operation of public utilities and Law No. 241/2006 on water supply and sewerage services. The Ministry of Development, Public Works and Administration also supports the approach of functional areas in different co-operation formats, such as CEMAT in 2017 or the PRES RO 2019 theme. In addition, the Law for Metropolitan Areas, adopted by Parliament in 2022, ensures a framework for co-operation, while administrative consortia are regulated through the Administrative Code. Together, they provide the legal basis for various co‑operative arrangements among local administrative units.

Romania’s legislation distinguishes several forms of inter-municipal co-operation, ranging from flexible partnerships to highly institutionalised legal entities.

• The least formalised mechanisms are inter-municipal agreements (acorduri de cooperare), concluded directly between two or more local governments to perform shared tasks or projects. They do not create a new legal entity and are typically used for temporary co-operation on specific administrative or service-delivery functions.

• A more structured and widespread instrument is the inter-community development association (IDA) (asociație de dezvoltare intercomunitară). IDAs are entities with legal personality under private law and of public utility, governed by their own statutes and operating under the Administrative Code. They can own property, employ staff, manage funds, and contract independently of their members. Each IDA is governed by a General Assembly of representatives from the member units, a Board of Directors, and a President (usually a mayor). IDAs are the main institutional vehicle for joint service provision – especially for utilities such as water, sewerage, solid waste management, or local transport – and for joint project implementation. Their importance increased after EU accession, as many investment programmes (e.g. for water and sanitation) required inter-municipal structures to access funding. However, challenges remain, including cumbersome decision making (often based on unanimity) and limited own-revenue capacity (Ghencea et al., 2025[155]).

• At a higher level of institutionalisation are metropolitan areas, a specific type of IDA created to promote integrated territorial development around urban centres. Initially introduced by Law No. 351/2001 and subsequently integrated into the Administrative Code, their framework was substantially revised by Law No. 246/2022 on Metropolitan Areas. The new law provides a formal legal basis for metropolitan governance, enabling county-seat municipalities and surrounding localities - up to two territorial rings beyond the core city - to form metropolitan areas. The entities have legal personality, may own assets, enter into contracts, and manage projects. Member local governments can delegate competencies to the metropolitan body in areas such as spatial planning, mobility, public services and infrastructure. For Bucharest, the law requires the metropolitan area to cover at least the territory of the adjacent Ilfov County. Implementation is still limited, with only a few metropolitan areas formally established, and difficulties remain concerning fragmented planning, voluntary membership, limited fiscal autonomy and administrative capacity (OECD, 2025[156]; Stoian C. Groza O. & Rusu A., 2024[157]; Ghencea et al., 2025[155]).

• A new and yet unimplemented form of inter-municipal co-operation is the administrative consortium, introduced by Law No. 372/2022, revised by Law No. 387/2023 that amends the Administrative Code, in line with Romania’s National Recovery and Resilience Plan (NRRP). These consortia are intended to enable neighbouring territorial units – regardless of county boundaries -  to voluntarily co‑operate to pool specialised human and administrative resources, attract investment and improve service quality. Administrative consortia were conceived as a more flexible mechanism, which can be approved by local councils (OECD, 2025[156]). However, as of 2025, the administrative consortium remains largely theoretical (Ghencea et al., 2025[155]). The use of this co-operation tool is likely to increase due to the implementation of the National Multiannual Program dedicated to administrative consortia, which is planned to be approved by Government Decision in 2026.

Overall, the use of inter-municipal co-operation in Romania remains limited and sector-specific, concentrated in utilities and infrastructure management. While recent legislation, especially Law No. 246/2022 and Law No. 372/2022, revised by Law No. 387/2023, which amends the Administrative Code, marks progress towards institutionalised metropolitan and inter-local governance, implementation remains uneven. Key constraints include voluntary membership, fragmented sectoral planning, limited financial incentives (no dedicated funding streams), and administrative capacity gaps. Nevertheless, inter-municipal co-operation has become increasingly important for accessing EU cohesion funds and promoting integrated territorial development in a highly fragmented local government landscape of over 3 200 units (Ghencea et al., 2025[155]).

Slovak Republic

Article 66 of the Constitution of the Slovak Republic guarantees municipalities the right to associate with other municipalities. This constitutional principle is operationalised through Act No. 369/1990 Coll. on Municipal Establishment, notably Chapters 20b-20f, which regulate the voluntary co-operation of municipalities (dobrovoľná spolupráca obcí) (Government of the Slovak Republic, 1990[158]). The Act provides multiple forms of co-operation that differ in their legal status, degree of formalisation and autonomy, from flexible contractual arrangements to fully institutionalised administrative bodies (OECD, 2025[159]).

• Contractual and project-based co-operation: The most flexible and least formalised form of inter-municipal co-operation enables municipalities to sign agreements to deliver specific services or implement common projects. These agreements do not create new legal entities and are often used for short-term co-operation in areas such as waste management, social services, culture and tourism. Funding comes from municipal budgets or external project-based sources (Klimovský & Nemec, 2021[160])

• Micro-regions (mikroregióny): Municipalities may establish voluntary associations for the joint promotion of local and regional development, environmental protection, tourism or spatial planning. Micro-regions are financed mainly through municipal contributions, own fundraising and EU Structural Funds. While they provide a platform for co-operation and project preparation, their activities depend on voluntary participation and limited administrative resources.

• Joint Municipal Offices (JMOs, spoločné obecné úrady): The most widespread and formalised model of co-operation, JMOs are established under Act No. 369/1990 Coll. to perform delegated state-administration tasks on behalf of several municipalities. They may cover up to 21 administrative domains, including building regulation, local communications, environmental protection and registry services. JMOs can include thematic sections that serve different clusters of municipalities. Since they carry out delegated competences, they receive central-government grants as well as financial contributions from participating municipalities. There are 106 JMOs in Slovak in 2023 (Ministry of Interior of Slovakia, 2025[161])

• Joint municipal companies: Municipalities can jointly establish commercial companies governed by private law to deliver public services such as waste management, water supply, sewage treatment or local tourism. These companies have independent legal personality and financial autonomy, but mainly focus on operational service delivery rather than territorial governance (CoE - Congress of Local and Regional Authorities,, 2023[162]) (OECD/UCLG, 2022[6]).

Finally, Slovakia is experimenting newly emerging model based on Centres of Shared Services. These pilot Centres are to be created in the least developed districts of the country as part of the Recovery and Resilience Plan. Although similar to the JMOs in that municipalities may participate on an ad hoc basis, these go one step further by allowing municipalities to co-operate on their original competencies as well as delegated ones (OECD, 2025[159]).

Finally, Slovakia makes a lot of use of EU-supported territorial co-operation initiatives: under LEADER/Community-Led Local Development (CLLD) framework, municipalities co‑operate with local stakeholders in Local Action Groups (LAGs) to prepare and implement integrated rural development strategies. Similar EU instruments – Integrated Territorial Investments (ITIs) and Sustainable Urban Development Areas (SUDAs) – encourage co-operation within functional territories. These forms strengthen horizontal collaboration but are primarily project-based and tied to EU programming cycles (OECD, 2025[159]).

Slovenia

Article 6 of the Local Self-Government Act (Government of Slovenia, 1993[163]) recognises municipalities’ right to co‑operate voluntarily to regulate and carry out local matters of public interest. Slovenia has a longstanding tradition of inter-municipal co-operation, with municipalities collaborating in a wide range of areas, most commonly water supply, waste management (collection and disposal), public transport, primary healthcare, road maintenance, disaster protection, public libraries, education and tourism (CoE - Congress of Local and Regional Authorities, 2025[164]).

The Act provides several instruments for inter-municipal co-operation, ranging from flexible agreements to more institutionalised entities. The Financing of Municipalities Act (Government of Slovenia, 2006[165]) further details the financial framework for these arrangements, including earmarked state grants and municipal co-financing.

• Contractual or project-based co-operation: Municipalities may conclude ad-hoc agreements to deliver specific services or implement common projects (e.g. road maintenance, cultural events, tourism). This is the least formalised form of co-operation; no new legal entity is created, and activities are typically financed from municipal budgets or external project funds.

• Interest associations / consortia (interesne zveze): These are single- or multi-purpose associations formed to carry out individual administrative tasks or joint investment programmes. They constitute a separate entity governed by a council composed of mayors and councillors and are commonly used for drinking water supply, wastewater treatment and environmental management (CoE - Congress of Local and Regional Authorities, 2025[164]).

• Joint municipal administrations (JMAs, “joint administration”): Two or more, often smaller, municipalities may establish a joint municipal administration (skupna občinska uprava) to perform selected administrative tasks collectively (e.g. building inspection, local police and wardens, internal audit, legal services, or spatial planning). According to Article 18 of the Financing of Municipalities Act, municipalities engaged in joint administration are eligible for earmarked state grants to cover part of the costs of joint programmes and investments, in addition to municipal contributions.

By the end of 2023, there were 38 joint municipal administrations employing 603 civil servants nationwide. The Ministry of Public Administration co-finances between 30% and 55% of employment costs (depending on the number of tasks and participating municipalities, plus 5% per additional task, with at least three municipalities required for eligibility), and up to 20% of other operating costs. In 2024, total state support amounted to approximately EUR 10 million. JMAs have proven particularly effective for inspection services, municipal wardens, internal audit, spatial planning, civil protection, budgeting/accounting, legal affairs, transport management and IT (CoE - Congress of Local and Regional Authorities, 2025[164]).

Municipalities are also permitted to establish associations or joint bodies for service provision and to co-found public institutions, funds, agencies or companies (including companies under private law) to manage and deliver local services such as water supply, waste management, transport, culture or tourism. These arrangements enable municipalities to pool resources and expertise, particularly where economies of scale are necessary for efficient service delivery.

Spain

The legal and institutional framework for inter-municipal co-operation in Spain is primarily established by the Basic Law on Local Government (Ley 7/1985, LBRL), complemented by regional legislation enacted by the Autonomous Communities (Government of Spain, 1985[166]). The Spanish system provides a broad set of mechanisms that enable municipalities to collaborate in the delivery of public services, infrastructure management, and territorial planning (Podadera & Colomina, 2025[167]). These range from flexible, ad hoc agreements to permanent public-law entities with autonomous budgets and governance:

• The simplest mechanisms are informal agreements and bilateral conventions (convenios de colaboración), authorised by Article 57 of the LBRL. These contractual arrangements allow municipalities to share resources or implement joint projects without creating a new entity. They are common for temporary or small-scale co-operation, such as tourism promotion, cultural events, or shared administrative personnel.

• A more structured form is the consortium (consorcio), regulated by Article 57 of the LBRL and the Law 40/2015 on the Legal Regime of the Public Sector. Consortia are public-law entities with legal personality that may include municipalities, provinces, Autonomous Communities, and even national or international bodies. They are widely used for transport systems, environmental services, emergency management, or cultural and social infrastructure.

• The mancomunidad is the most common and traditional inter-municipal co-operation form, explicitly recognised in Article 44 of the LBRL. As of 2023, there were over 1 000 active mancomunidades grouping more than 3 500 municipalities (Podadera & Colomina, 2025[167]). As of 2023, there were over 1 000 active mancomunidades grouping more than 3 500 municipalities (Podadera & Colomina, 2025[167]). These voluntary associations of municipalities have legal personality and their own statutes, governance bodies, assets, and budgets. They are established by agreement among municipalities and approved by the Autonomous Community. Mancomunidades typically deliver shared services such as water supply, waste management, transport, environmental protection, or social services, especially in rural and low-density areas.

• Several regions have introduced enhanced variants, such as the Mancomunidades de Interés General (MIGs) in Castilla y León, designed to strengthen co-operation and improve service delivery in depopulating territories. Other autonomous communities have established regional variants of such associations of municipalities of regional interest, for example, mancomunidades de municipios de interés autonómico (Toscano Gil Francisco, 2025[168]; OECD, 2025[169]). Mancomunidades rely mostly on regional and municipal funding (OECD/UCLG, 2022[6]) (CoE - Congress of Local and Regional Authorities,, 2021[170]).

• Comarcas represent a higher level of institutionalisation. They are territorial entities established by regional law as an intermediate tier between municipalities and provinces, with permanent administrative status. Unlike mancomunidades, comarcas are not voluntary. They are defined and regulated by each Autonomous Community. Their competences generally include spatial planning, local development, infrastructure co‑ordination, and service delivery. Strong comarca systems exist in Aragón, Catalonia, and Galicia, while other regions have adopted partial or flexible approaches.

At the most formalised end, Article 43 of the LBRL authorises the Autonomous Communities to create metropolitan areas (áreas metropolitanas) by regional law. These entities ensure integrated governance of large urban regions, co‑ordinating urban planning, transport, housing, environment, and infrastructure across municipal boundaries. The best-known example is the Área Metropolitana de Barcelona (AMB), created by Catalan Law 31/2010, uniting 36 municipalities under a single metropolitan authority with fiscal autonomy and elected representation. In regions without a formal área metropolitana, mancomunidades often serve as functional alternatives for service co‑ordination, though with more limited competences and weaker institutional integration (Council of Europe, 2022[171]).

The Law 27/2013 on the Rationalisation and Sustainability of Local Administration promotes co-operation by linking financial incentives to efficiency gains. Municipalities that co‑ordinate or merge services and demonstrate cost savings can receive additional state transfers (Bel et al., 2022[172]). However, implementation remains uneven across regions, reflecting Spain’s decentralised governance structure. Inter-municipal co-operation is particularly relevant in addressing the challenges of municipal fragmentation and rural depopulation, where joint service delivery is essential to maintain basic infrastructure and social services (OECD, 2025[169]).

Overall, inter-municipal co-operation in Spain is both diverse and asymmetrical, with structures varying significantly among Autonomous Communities depending on their legislation, geography, and political priorities. This diversity reflects Spain’s multi-level governance model, in which regional governments play a decisive role in shaping inter-municipal structures and promoting territorial cohesion (Podadera & Colomina, 2025[167]).

Sweden

The framework for inter-municipal co-operation is defined by the Local Government Act (SFS 2017:725), which replaced the 1991 Act. This legislation provides municipalities and regions with flexible legal instruments to collaborate in carrying out statutory responsibilities and public services. There are four main forms of co‑operation: contracts, “joint committee”, “municipal federation” and entities under private law.

• Contractual co-operation (avtalssamverkan) is the least formalised form of co-operation. It is regulated under Chapter 9, Section 37, of the Local Government Act. These bilateral or multilateral agreements do not create a separate legal entity and are widely used to share administrative and regulatory functions, staff, or infrastructure. They are applicable across most policy areas (OECD/UCLG, 2022[6]; Swedish Association of Local Authorities and Regions (SALAR), 2024[173]). The advantages of this form are its simplicity and flexibility, while the limitations lie in the limited control over day-to-day operations and the complex legal scope.

• A more structured but still relatively flexible form of inter-municipal co-operation is the joint committee (gemensam nämnd), regulated under Chapter 9, Section 31 of the Local Government Act. Two or more municipalities (or a municipality and a region) may establish a joint committee to perform common tasks. A joint committee operates within the organisational structure of one of the member municipalities, which serves as the host authority. It does not have its own legal personality; its composition, duties, and financial arrangements are defined in the co-operation agreement. Joint committees are particularly common in planning and building control, environmental health, IT, HR, upper-secondary education, and guardianship services (Swedish Association of Local Authorities and Regions (SALAR), 2026[174]). The advantages of this form are clear governance and accountability with limited organisational overheads. However, it can become unwieldy with partners. (Swedish Association of Local Authorities and Regions (SALAR), 2026[174]).

• The most formalised form, as well as the most common, is the municipal federation (kommunalförbund), governed by Chapter 9, Sections 37-52 of the Local Government Act. Municipal federations are independent legal entities under public law, with their own legal capacity, independent of the members, whose tasks and obligations are formally agreed upon by their members. They can be created by two or more municipalities (or a municipality and a region) to jointly perform delegated responsibilities that are transferred to the municipal federation. Each federation has its own assembly, board, budget, and staff. They can own property, enter into contracts, and manage operations independently, but cannot levy taxes.

  This form is best suited for regulatory and specialised functions (e.g. environmental health, infrastructure, rescue services, energy, water and wastewater). Financing is provided through member contributions, which are usually based on population or service usage. This approach allows for efficiency, strong specialisation and separate finances between municipalities. However, it can also create a risk of excessive autonomy and reduced influence for each municipality (Swedish Association of Local Authorities and Regions (SALAR), 2026[174]).

• Swedish municipalities may also co‑operate through limited-liability companies or foundations under private law, when permitted by the Local Government Act and national company law. These structures are widely used for utilities, housing, energy, and broadband provision, often owned jointly by several municipalities.

As of 2021-22, Sweden had about 85 municipal associations and 122 joint committees, with around four-fifths of municipalities participating in at least one of each form. Swedish municipalities collaborate only to a limited extent in cost-intensive, citizen-facing areas such as schools and elderly care, reflecting the importance of maintaining local political control in these sectors. The (Statskontoret, 2023[175]) finds that co‑operation is instead more common in less politically sensitive and more specialised activities, such as rescue services, environmental regulation, and administrative functions like IT and procurement. It is also increasingly applied to housing provision, especially in integrated housing and labour-market regions (Agace A., 2024[176]). While there is some potential to expand co‑operation, (Statskontoret, 2023[175]) suggests it is most feasible in specialised or low-volume tasks rather than large welfare services.

Switzerland

In Switzerland, the legal framework for inter-municipal co-operation is determined by cantonal constitutions and laws, as the Federal Constitution (Art. 50) merely guarantees municipal autonomy but does not regulate co-operation. Municipalities therefore, organise their joint activities according to cantonal provisions, which define the permissible forms, procedures and governance of co‑operative entities. Swiss municipalities participate very intensively in inter-municipal co-operation, often belonging to 8‑12 co‑operative bodies each, from the least formal to the most institutionalised arrangements.

The simplest form of collaboration is the inter-municipal agreement or convention (interkommunale Vereinbarung / accord intercommunal), where municipalities contractually decide to manage a service or project together. No separate legal entity is created, and decisions taken by a joint committee must be ratified by each participating municipality. These arrangements are widespread in education support services, spatial planning, water management, and local infrastructure (CoE - Congress of Local and Regional Authorities,, 2017[177]).

Several cantons allow municipalities to establish joint public-law institutions (interkommunale Anstalt). These bodies operate with their own management rules, separate accounts and staff, while the founding municipalities retain ownership and strategic control. They are commonly used for shared facilities, ICT, or utilities (Kanton Argau, 2019[178]).

The most common and institutionalised form of inter-municipal co-operation is the public-law association of municipalities (Zweckverband / Gemeindeverband / association de communes). These entities possess legal personality, their own governing bodies, budgets and accounts, and may own assets. Depending on the cantons, they can be single or multiple purpose. They typically manage waste treatment, water and wastewater services, firefighting and rescue, primary education or regional planning. In the Canton of Zürich, for example, there were 141 Zweckverbände as of January 2023, covering a wide range of functions.

A further form of institutionalised inter-municipal co-operation is the regional conference (Regionalkonferenz / conférence régionale), created under cantonal law to co‑ordinate strategic planning, public transport, spatial development and regional policy. In cantons such as Bern, Vaud, Geneva or Valais, regional conferences have decision making powers, can adopt regional spatial plans and act as the main vehicle for inter-municipal strategic co‑ordination. They bridge the gap between service-based associations and metropolitan governance platforms.

Municipalities may also co‑operate through limited joint companies or foundations under private law, when compatible with cantonal and municipal legislation. These structures are particularly common for utilities, waste management, energy, broadband, and housing services (OECD/UCLG, 2022[6]).

At the metropolitan level, Switzerland has no formal metropolitan authorities, but it has strong metropolitan governance platforms, including Greater Geneva / Grand Genève, the Trinational Eurodistrict Basel (TEB) and the Zurich Metropolitan Conference, which bring together municipalities, cantons and cross-border partners for strategic development and transport co‑ordination. There is also a network of intermunicipal associations, joint bodies, and sectoral co-operation mechanisms that play a crucial compensatory role in the absence of metropolitan governments (Kübler & Rochat, 2018[179]).

Switzerland has a system of both compulsory and incentive-based co-operation. Some cantons have legally compelled municipalities to co‑operate in a specific field of competence (CoE Congress of Local and Region Authorities, 2007[180]). For example, according to the Loi sur les communes and sectoral cantonal legislation, municipalities of the Canton of Vaud are obliged to belong to inter-municipal associations for waste treatment, civil protection, and fire services (CoE - Congress of Local and Regional Authorities,, 2017[177]). Cantons also often resort to financial incentives, such as additional transfers, temporary subsidies or co-financing eligibility

Türkiye

The legal framework for inter-municipal co-operation in the Republic of Türkiye (hereafter “Türkiye”) is primarily provided by Law No. 5393 on Municipalities (Republic of Türkiye, 2005[181]) and Law No. 5355 on Local Administrative Unions (2005) complemented by the Metropolitan Municipality Law No. 5216 and the Special Provincial Administration Law No. 5302. These laws grant municipalities the right to collaborate with one another or with other public institutions for the joint provision of services or the implementation of projects of shared interest (Şemşit Eylemer & Erdoğan, 2025[182])

Under Law No. 5393, municipalities may establish joint service projects or partnership agreements (ortak hizmet projeleri) without creating a new legal entity. These flexible arrangements are based on written protocols approved by each municipal council and define the scope, financial contributions and administrative responsibilities of participating partners. They are typically used for limited-purpose co-operation, for instance, in infrastructure works, waste collection, transport, urban renewal, or cultural and social services. These agreements allow municipalities to pool resources or share facilities while maintaining full legal and budgetary independence.

The more institutionalised and durable form of inter-municipal co-operation is the municipal union (belediye birliği), regulated by Law No. 5355 on Local Administrative Unions (2005). A municipal union is a public-law legal entity formed by at least two municipalities - and sometimes by special provincial administrations - to perform specific public functions jointly. Each union has its own governance structure, consisting of a Union Council (composed of mayors and councillors from member municipalities), an Executive Committee, and a President elected from among the members. Municipal unions may adopt independent budgets, employ staff, own property and make binding decisions within their legally defined areas of activity.

Municipal unions operate across a range of functional areas, particularly in environmental management, solid waste collection and disposal, water and wastewater services, local transport, fire and emergency services, tourism promotion, and regional development projects. Many have been instrumental in implementing EU-funded projects, especially in the fields of wastewater treatment, renewable energy, and disaster resilience. By 2024, there were over 350 active municipal unions in Türkiye, varying in size and scope (CoE - Congress of Local and Regional Authorities,, 2022[183]; Şemşit Eylemer & Erdoğan, 2025[182]).

It is important to mention that metropolitan municipalities in Türkiye are not a form of inter-municipal co-operation. They result from legally mandated territorial consolidation and administrative restructuring, not from voluntary collaboration among municipalities. They constitute a separate tier of local government, distinct from both ordinary municipalities and inter-municipal co-operation mechanisms.

Overall, despite a comprehensive legal foundation, inter-municipal co-operation remains constrained by Türkiye’s highly centralised administrative system and limited local fiscal autonomy. Smaller municipalities often depend on central transfers, which can limit their capacity to contribute to joint initiatives. Nonetheless, municipal unions and joint service partnerships have become key mechanisms for achieving economies of scale, improving service quality, and co‑ordinating infrastructure investments across municipal boundaries (Şemşit Eylemer & Erdoğan, 2025[182]).

United Kingdom

The United Kingdom combines a strong tradition of voluntary collaboration among councils with distinctive legal and institutional frameworks in each of its four nations. The general legal basis derives from the Local Government Act 1972 (Government of the United Kingdom, 1972[184]), which allows delegation of functions, establishment of joint committees and joint staff arrangements (Sections 101-102, 113). This provides a foundation for inter-municipal co-operation in the form of shared services, joint procurement, and mutual aid agreements between neighbouring authorities.

The UK’s multi-level governance structure means that the institutional landscape for co-operation varies substantially across England, Wales, Scotland and Northern Ireland. While most collaboration remains voluntary and service-oriented, successive reforms have encouraged councils to pool capacity and co‑ordinate strategy through regional and sub-regional arrangements (OECD/UCLG, 2022[6]; CoE - Congress of Local and Regional Authorities, 2022[185]).

England

In England, the Localism Act 2011 introduced a general power of competence, enabling councils to do anything an individual may, provided the activity is not expressly prohibited by law (Government of the United Kingdom, 2011[186]). This broad power underpins a wide range of informal partnerships and formal shared-service arrangements, typically created under Sections 101-102 of the Local Government Act 1972 (delegation and joint committees) and Section 113 (staff sharing). Such arrangements support a diverse set of joint services, including environmental health, ICT, internal audit, revenues and benefits, and building control.

At a more institutionalised level, the Cities and Local Government Devolution Act 2016 and the Levelling up and Regeneration Act 2023 allow councils to form Combined Authorities (CAs) and Combined County Authorities (CCAs) – also known as ‘strategic authorities’ (SAs) – statutory sub-regional bodies that exercise joint powers over transport, skills and spatial planning, often under a directly elected mayor, in order to drive growth at a local level. Some SAs can receive an ‘Integrated Settlement’ which provides significant new funding flexibilities, allowing Mayors to spend money in a way that better reflects their local priorities and empowering them to make the strategic policy decisions necessary to foster growth and deliver better outcomes for their residents. The 2025 English Devolution and Community Empowerment Act aims to achieve wider SA coverage across England, introducing Foundation Strategic Authorities (FSAs) alongside Mayoral Strategic Authorities, offering local areas tiered devolution models with increasing powers and fiscal flexibility. In line with this, it also proposes the introduction of Established Mayoral Strategic Authorities” (EMSAs), which gives mayors the right to request new powers. In England, devolution arrangements for existing SAs already illustrate how strong relationships between central government and SAs can foster deeper co-operation and strengthen multi-level governance.

In metropolitan regions such as Greater Manchester, Liverpool City Region, and the West Midlands, SAs now oversee transport systems, housing strategies, and green infrastructure plans, and this is being rolled out to more rural and mixed environment areas with the creation of new SAs. According to the Annual Report on English Devolution 2024-25, with the creation of the four new CAs and CCAs established in 2024-25 (Hull & East Yorkshire, Greater Lincolnshire, Lancashire, and Devon & Torbay), approximately 51.5% of England is now covered by devolution (Ministry of Housing Communities & Local Government, 2025[187]). Alongside these statutory structures, informal co-operation and service-sharing remain the predominant and most flexible forms of inter-municipal co-operation.

The Government has also established new engagement forums to enhance the devolution framework. The Mayoral Council and Leaders Council are convened by the Ministry of Housing, Communities and Local Government, providing flagship forums for local leaders to engage with central government and with each other on a formal basis. Through the Mayoral Council, Mayors are able to bring local insights to bear on shared national problems and ensure the interests of their local communities are represented in the development of government policy. The Leaders Council brings together ministers and leaders who represent different parts of the local government sector to discuss matters where they can work together to achieve better policy outcomes, such as building new homes and delivering a ten-year health plan. Actions taken forward from the group can lead to further co-operation, for example, commissioning a local and central government taskforce on giving children the “best start in life”.

Wales

In Wales, inter-municipal co-operation has been progressively formalised under the Local Government and Elections (Wales) Act 2021, which created Corporate Joint Committees (CJCs) as permanent regional bodies. CJCs bring together groups of local authorities to co‑ordinate strategic planning, transport and economic development across four regional footprints (North, Mid, South-East and South-West Wales). They possess corporate status, can employ staff and hold assets, and are subject to the same governance and audit rules as local authorities (OECD, 2024[188]; OECD, 2020[189]). Voluntary inter-municipal partnerships continue at the service level, particularly for regulatory services, ICT, procurement and waste management. The regional geographies of the CJCs align with those used by the four City and Growth Deals in Wales as part of their governance and delivery structures. The regional geographies of the CJCs are reflected in the design of regional investment programmes. For example, the four City and Growth Deals in Wales align to the CJC footprint, with two of the four Deals formally integrating governance and delivery structures into the CJC.

The law also provides basic governance requirements while allowing regions to customise the governance arrangements as they see fit. CJC regulations specify the membership of the governing body: a decision maker from each constituent council and from the relevant national parks. Each CJC can designate new members with a fixed term and with specified voting powers. The CJCs can establish sub-committees and are obliged to constitute a governance and audit sub-committee. The law includes a suite of other requirements: publishing a constitution, complying with a code of conduct, maintaining a general fund and managing records. Despite leeway in the regulations for different functions and governance models, some local authorities expressed concern that the CJCs represent a one-size-fits-all approach to managing regional working. Voluntary regional working has taken different forms across Wales, in terms of the territorial footprint, functions and governance to respond to regional differences. The framework provided in law, even if it only establishes the skeleton of what the CJCs and their work will look like, represents a significant change from the status quo and risks appearing like a uniform approach that fails to address regional differences (OECD, 2024[190]). To mitigate these risks, a Strategic Partnership Agreement and a position statement on regional collaboration have been put in place to emphasise that CJCs are not intended as a one-size-fits-all approach.

Scotland

Scottish councils collaborate through shared-service arrangements, regional economic partnerships, and City Region and Growth Deals, which unite councils, universities, businesses and both the Scottish and UK Governments for co‑ordinated investment. The Local Government etc. (Scotland) Act 1994 permits the establishment of joint committees and joint boards for shared service delivery across local authority boundaries. The Local Government Scotland Act 2003 introduced a Best Value duty requiring local authorities to secure continuous improvement by collaborating with others and enabling shared contracts and supply of services. The Public Bodies (Joint Working) (Scotland) Act 2014 established Integration Joint Boards to enable delegated and jointly managed delivery of health and social care services across multiple local authorities. Community Planning Partnerships, introduced by the Community Empowerment (Scotland) Act 2015, provide an additional statutory platform for multi-agency co-operation.

Northern Ireland

The Local Government Act (Northern Ireland) 2014 (Northern Ireland - Department for Communities, 2025[191]), introduced Community Planning as a statutory process requiring each of the 11 councils to convene a partnership of public agencies and community representatives to agree on local priorities. Although this mechanism enhances co‑ordination, it constitutes multi-stakeholder governance rather than classic inter-municipal co-operation.

By contrast, functional inter-council partnerships – notably arc21, a corporate body uniting six councils for waste management – represent genuine inter-municipal co-operation. Similar arrangements include the North West Region Waste Management Group and the Northern Ireland Resource Network, which jointly procure services and manage infrastructure. Co-operation also occurs through City and Growth Deals, which bring together councils, government departments and universities for regional investment, such as the Belfast Region City Deal signed in 2023.

United States

Inter-municipal co-operation in the United States is largely determined by state law. There is no federal framework governing municipal collaboration. Instead, states establish their own enabling statutes and incentives for joint action among local governments.

Local level co-operation

At the local level, co-operation takes two main forms:

• Special-purpose governments such as school districts, water and sewer authorities, fire protection districts, or transit agencies. They are legally separate entities created to deliver specific services across multiple jurisdictions.

• Formal shared-service arrangements. These are voluntary or contractual agreements through which municipalities jointly provide or procure services. These arrangements are often based on state “home rule” provisions or interlocal co-operation acts, first introduced in the 1950s-60s and now enacted in nearly every state.

Most states permit municipalities to enter joint powers agreements (JPAs) or interlocal contracts that define shared services, governance, cost-sharing, and accountability. Some states actively promote inter-municipal co-operation through state-led shared-service programs or technical assistance.

Metropolitan-scale co-operation

Since the 1960s, both state and federal governments have promoted co-operation at the metropolitan level to address cross-jurisdictional issues such as transport, housing, and land use. Federal transportation legislation, notably the Federal-Aid Highway Act (1962) and the Urban Mass Transportation Act (1964), mandated the creation of Metropolitan Planning Organizations (MPOs) in all urbanised areas with populations over 50 000. MPOs bring together cities, counties, and transit agencies to prepare long-range transportation plans and allocate federal infrastructure funding. There are now approximately 410 MPOs operating nationwide in 2024 (Federal Highway administration, 2025[192]).

In parallel, Councils of Governments (COGs) emerged as voluntary regional bodies that co‑ordinate planning, data, and policy exchange among municipalities and counties. While not mandated by federal law, COGs often overlap with MPOs and serve as their administrative hosts in many metropolitan areas (e.g. the Metropolitan Washington Council of Governments, the North Central Texas Council of Governments).

Both MPOs and COGs play a critical role in metropolitan and regional governance, extending inter-municipal co-operation into strategic domains such as climate resilience, housing, and emergency management. Federal agencies-including the Department of Transportation (DOT), Department of Housing and Urban Development (HUD), and Federal Emergency Management Agency (FEMA)-support their co‑ordination through targeted grant programmes (e.g. Reconnecting Communities Pilot Program and Resilience Hubs Initiative). (OECD/UCLG, 2022[6]).

References

[176] Agace A. (2024), “Exploring Inter-Municipal Cooperation and Housing Provision in Sweden,”, DIVA Portal, Linköping University., https://www.diva-portal.org/smash/get/diva2%3A1990077/FULLTEXT02.pdf.

[69] Angelidis (2025), Greece: Significant but Insufficient Advancements in Horizontal Intergovernmental Cooperation, https://link.springer.com/book/10.1007/978-3-031-83567-4.

[134] Arntsen, B., D. Torjesen and T. Karlsen (2021), “Asymmetry in inter-municipal cooperation in health services – How does it affect service quality and autonomy?”, Social Science & Medicine, Vol. 273, https://doi.org/10.1016/j.socscimed.2021.113744.

[41] Bakoš, E. et al. (2021), “The perception of inter-municipal cooperation by local officials and managers”, Central European Journal of Public Policy, Vol. 15/1, pp. 1-14, https://doi.org/10.2478/cejpp-2021-0002.

[113] Banque Centrale du Luxembourg (2012), Bulletin BCL 2012, https://www.bcl.lu/fr/publications/bulletins_bcl/BCLAnalyse/encadres/20123E17.pdf.

[65] Behnke, N. (ed.) (2025), Manifestations of a Cooperative Federal Tradition: Horizontal Coordination in Germany.

[172] Bel, G. et al. (2022), Styles of inter-municipal cooperation and the multiple principal problem: a comparative analysis of European economic area countries, https://doi.org/10.1080/03003930.2022.2041416.

[160] Brezovnik, H. (ed.) (2021), Local Self-Government in Slovakia, https://doi.org/10.4335/978-961-7124-00-2.

[4] Butt, K. et al. (2020), Local government co-ordination: metropolitan governance in twenty-first century Australia,, AHURI Final Report No. 352, Australian Housing and Urban Research Institute Limited, Melbourne,, https://www.ah.

[57] Chebarova M. & Eerma D. (2025), Estonia: Inter-municipal and Cross-border Cooperation Within a Decentralised Polity and EU Framework.

[164] CoE - Congress of Local and Regional Authorities (2025), Monitoring of the application of the European Charter of Local SelfGovernment in Slovenia, https://search.coe.int/congress#{%22CoEIdentifier%22:[%2209000016808e600f%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[185] CoE - Congress of Local and Regional Authorities (2022), Monitoring of the application of the European Charter of Local Self Government in the United Kingdom, https://rm.coe.int/0900001680a5b483.

[7] CoE - Congress of Local and Regional Authorities (2022), Monitoring of the Application of the European Charter of Local Self-Government in Belgium, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680a863d3%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[48] CoE - Congress of Local and Regional Authorities (2022), Monitoring of the application of the European Charter of Local Self-Government in Denmark, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680a8636c%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[66] CoE - Congress of Local and Regional Authorities (2022), Monitoring of the application of the European Charter of Local Self-Government in Germany, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680a5b17c%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[11] CoE - Congress of Local and Regional Authorities (2021), Monitoring of the application of the European Charter of Local SelfGovernment in Bulgaria, https://rm.coe.int/CoERMPublicCommonSearchServices/DisplayDCTMContent?documentId=0900001680a28bb8.

[60] CoE - Congress of Local and Regional Authorities, (2024), Monitoring of the application of the European Charter of Local Self-Government in Finland, https://rm.coe.int/monitoring-of-the-application-of-the-european-charter-of-local-self-go/1680b1d064.

[92] CoE - Congress of Local and Regional Authorities, (2024), Monitoring of the application of the European Charter of Local Self-Government in Italy, https://search.coe.int/cm#{%22CoEIdentifier%22:[%220900001680aec7e1%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[135] CoE - Congress of Local and Regional Authorities, (2024), Monitoring of the application of the European Charter of Local Self-Government in Norway, https://search.coe.int/cm#{%22CoEIdentifier%22:[%220900001680aec7e0%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[107] CoE - Congress of Local and Regional Authorities, (2024), Monitoring the implementation of the European Charter of Local Self-Government in Latvia., https://rm.coe.int/suivi-de-l-application-de-la-charte-europeenne-de-l-autonomie-locale-e/1680b1ce12.

[56] CoE - Congress of Local and Regional Authorities, (2023), Monitoring of the application of the European Charter of Local Self-Government in Estonia, https://search.coe.int/cm#{%22CoEIdentifier%22:[%220900001680ace162%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[162] CoE - Congress of Local and Regional Authorities, (2023), Monitoring the application of the European Charter of Local Self-Government in the Slovak Republic, https://search.coe.int/cm#{%22CoEIdentifier%22:[%220900001680acd77d%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[183] CoE - Congress of Local and Regional Authorities, (2022), Monitoring of the application of the European Charter of Local SelfGovernment in Turkey, https://rm.coe.int/0900001680a5b1d3.

[170] CoE - Congress of Local and Regional Authorities, (2021), Monitoring of the application of the European Charter of Local Self-Government in Spain, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680a4210d%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[122] CoE - Congress of Local and Regional Authorities, (2021), Monitoring of the application of the European Charter of Local Self‑Government in the Netherlands, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680a42001%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[76] CoE - Congress of Local and Regional Authorities, (2021), Monitoring of the European Charter of Local Self-Government in Hungary, https://rm.coe.int/monitoring-of-the-european-charter-of-local-self-government-in-hungary/1680a129f6.

[146] CoE - Congress of Local and Regional Authorities, (2019), Local and regional democracy in Poland, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680939003%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[177] CoE - Congress of Local and Regional Authorities, (2017), Local and regional democracy in Switzerland, https://search.coe.int/congress#{%22CoEIdentifier%22:[%220900001680750d61%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[79] CoE - Congress of Local and Regional Authorities, (2017), Local Democracy in Iceland, https://search.coe.int/congress#{%22CoEIdentifier%22:[%2209000016806fc29b%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[70] CoE - Congress of Regional and Local Authorities (2015), Local and regional democracy in Greece, https://search.coe.int/congress#{%22CoEIdentifier%22:[%22090000168071980e%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[180] CoE Congress of Local and Region Authorities (2007), The Institutional Framework of Inter-Municipal Co-operation, https://rm.coe.int/the-institutional-framework-of-inter-municipal-co-operation/1680719b6a.

[63] Congress of Local and Regional Authorities (2024), Monitoring of the application of the European Charter of Local Self-Government in France, https://www.congress-monitoring.eu/en/1-pays.html.

[83] Congress of Local and Regional Authorities (2023), Monitoring of the application of the European Charter of Local Self-Government in Ireland, https://search.coe.int/cm#{%22CoEIdentifier%22:[%220900001680acd809%22],%22sort%22:[%22CoEValidationDate%20Descending%22]}.

[136] Congress of the Republic (1993), Constitución Política del Perú, Art. 194, https://www.venice.coe.int/webforms/documents/default.aspx?pdffile=CDL-REF%282019%29026.

[80] Council of Europe (2024), 2024, https://rm.coe.int/monitoring-of-the-application-of-the-european-charter-of-local-self-go/1680b1bd8b.

[36] Council of Europe (2024), Monitoring of the application of the European Charter of Local SelfGovernment in Croatia, https://rm.coe.int/monitoring-of-the-application-of-the-european-charter-of-local-self-go.

[171] Council of Europe (2022), Governance of European metropolitan areas, https://rm.coe.int/overview-governance-of-european-metropolitan-areas-ceggpad20227/1680aef4ec.

[71] Council of Europe (2018), Inter-municipal cooperation in Greece, https://rm.coe.int/inter-municipal-cooperation-imc-in-greece-final-report/168086d616.

[129] Crawford, Ron; Shafie, Hamed (2019), Scope and funding of local government: an international comparison, https://www.treasury.govt.nz/sites/default/files/2024-05/pc-wp-scope-and-funding-of-local-government-an-international-comparison.pdf.

[127] Department of Internal Affairs (2023), Future for Local Government Review - He piki tūranga, he piki kōtuku, https://www.dia.govt.nz/diawebsite.nsf/Files/Future-for-Local-Government/$file/Te-Arotake_Final-report.pdf.

[115] Depetris-Chauvin, E., R. Durante and E. Gutierrez (2024), Political Alignment and Inter-jurisdictional Cooperation in a Fragmented Political Landscape: Evidence from Mexico, https://scioteca.caf.com/bitstream/handle/123456789/2298/Political%20Alignment%20and%20Inter-jurisdictional%20Cooperation%20in%20a%20Fragmented%20Political%20Landscape_Evidence%20from%20Mexico.pdf?sequence=1&isAllowed=y.

[62] DGCL (2025), Guide de l’intercommunalité, https://www.collectivites-locales.gouv.fr/files/Institution/2.%20Structures%20territoriales/EPCI/guide%20interco%202025/guide%20interco%202025%20vf.pdf.

[29] DNP (2023), National Development Plan, https://colaboracion.dnp.gov.co/CDT/Prensa/Publicaciones/plan-nacional-de-desarrollo-2022-2026-colombia-potencia-mundial-de-la-vida.pdf.

[64] Federal Constitutional Court (2014), BVerfGE 138, 1, 17ff, https://www.bundesverfassungsgericht.de/EN/Decisions/DecisionsPublishedInTheOfficialDigest/_functions/akkordeon_band130-139.html.

[192] Federal Highway administration (2025), METROPOLITAN PLANNING ORGANIZATION (MPO) DATABASE, https://www.planning.dot.gov/mpo/.

[155] Ghencea et al. (2025), Romania: Horizontal Coordination in a Unitary Nation-State, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_14.

[15] Government of Alberta (2025), Intermunicipal collaboration frameworks, https://www.alberta.ca/intermunicipal-collaboration-framework.

[17] Government of Chile (2009), Constitutional reform on Municipal Associations, https://www.bcn.cl/leychile/navegar?idNorma=1002169.

[28] Government of Colombia (2013), Ley Orgánica 1625 Régimen para las Áreas Metropolitanas., https://www.funcionpublica.gov.co/eva/gestornormativo/norma.php?i=52972.

[20] Government of Colombia (2011), Ley 1454 de 2011 – Ley Orgánica de Ordenamiento Territorial (LOOT), https://www.anla.gov.co/07rediseureka2024/normativa/leyes/ley-1454-de-2011-ley-organica-de-ordenamiento-territorial-loot.

[30] Government of Costa Rica (1998), Codigo Municipal, https://www.tse.go.cr/pdf/normativa/codigomunicipal.pdf.

[34] Government of Croatia (2001), LAW ON LOCAL AND REGIONAL SELF-GOVERNMENT, http://www.parliament.am/library/Tim/XORVATIA.pdf.

[45] Government of Czechia (2023), Act No. 418/2023 Coll., https://www.zakonyprolidi.cz/cs/2023-418.

[39] Government of Czechia (2000), Act on Municipalities, https://www.zakonyprolidi.cz/translation/cs/2000-128?langid=1033.

[47] Government of Denmark (2019), Act on Local Government, https://www.elections.im.dk/media/22544/act-on-local-government.pdf.

[50] Government of Estonia (2014), Local Government Organisation Act, https://www.riigiteataja.ee/en/eli/509012014003/consolide.

[58] Government of Finland (2015), Municipal Act, http://www.parliament.am/library/Tim/finlandia.pdf.

[61] Government of France (1996), General law on Local Government, https://www.legifrance.gouv.fr/codes/texte_lc/LEGITEXT000006070633/.

[68] Government of Greece (2006), Municipalities and Communities Code, https://www.kodiko.gr/nomothesia/document/43235/nomos-3463-2006.

[75] Government of Hungary (2011), Cardinal Law on Local Self-Government, https://net.jogtar.hu/jogszabaly?docid=a1100189.tv.

[77] Government of Iceland (2011), Local Authorities Act, https://www.government.is/lisalib/getfile.aspx?itemid=86cd80de-940e-11e9-9442-005056bc530c.

[81] Government of Ireland (2001), Local Government Act, https://www.irishstatutebook.ie/eli/2001/act/37.

[91] Government of Italy (2014), Law on Metropolitan Cities, Provinces, and the Unions and Mergers of Municipalities, https://www.normattiva.it/uri-res/N2Ls?urn:nir:stato:legge:2014-04-07;56!vig.

[89] Government of Italy (2000), TUEL, https://dait.interno.gov.it/finanza-locale/documentazione/testo-unico-delle-leggi-sullordinamento-degli-enti-locali.

[94] Government of Japan (2025), 1947 Local Autonomy Act, https://laws.e-gov.go.jp/law/322AC0000000067.

[102] Government of Korea (2022), SPECIAL ACT ON SUPPORT FOR DEPOPULATION REGIONS, https://faolex.fao.org/docs/pdf/kor219723.pdf.

[98] Government of Korea (2021), Local Autonomy Act, https://elaw.klri.re.kr/eng_mobile/ganadaDetail.do?hseq=57596&type=abc&key=LOCAL%20AUTONOMY%20ACT¶m=L.

[104] Government of Latvia (2022), Law on Local Governments, https://likumi.lv/ta/id/336956-pasvaldibu-likums.

[111] Government of Lithuania (2020), National Progress PLan 2021-2023 (Nacionalinis pažangos planas), https://lrv.lt/uploads/main/documents/files/NPP%20planas.pdf.

[108] Government of Lithuania (2017), Law on Local Self Government.

[112] Government of Luxembourg (1988), Communal Law, https://legilux.public.lu/eli/etat/leg/loi/1988/12/13/n1/jo.

[117] Government of Mexico (2016), General Law on Human Settlements, Territorial Planning and Urban Development, https://www.diputados.gob.mx/LeyesBiblio/pdf/LGAHOTDU.pdf.

[120] Government of Netherlands (1992), Municipal Act, https://www.government.nl/documents/regulations/2014/09/25/municipalities-act.

[125] Government of New Zealand (2002), Local Government Act, https://www.legislation.govt.nz/act/public/2002/0084/latest/DLM170873.html.

[130] Government of Norway (2018), Local Government Act, https://www.regjeringen.no/en/dokumenter/the-local-government-act/id2672010/.

[131] Government of Norway (1999), Intermunicipal Companies Act, https://lovdata.no/dokument/NL/lov/1999-01-29-6.

[137] Government of Peru (2007), Ley N° 29029 - Ley de la Mancomunidad Municipal, https://www.leyes.congreso.gob.pe/documentos/leyes/29029.pdf.

[147] Government of Poland (2015), Act of 25 June 2015 amending the act on local government and certain other acts , Journal of Laws 2015, item 1045, ISAP, https://isap.sejm.gov.pl/isap.nsf/DocDetails.xsp?id=WDU20150001045.

[144] Government of Poland (1990), Law on Municipal Governments, https://lovdata.no/dokument/NL/lov/1999-01-29-6.

[152] Government of Portugal (2013), Legal Framework for Local Authorities.

[165] Government of Slovenia (2006), Municipal Financing Act, https://pisrs.si/pregledPredpisa?id=ZAKO4615.

[163] Government of Slovenia (1993), Local Self-Government Act, https://pisrs.si/pregledPredpisa?id=ZAKO307.

[166] Government of Spain (1985), Basic Law on Local Government, https://www.boe.es/buscar/act.php?id=BOE-A-1985-5392.

[123] Government of the Netherlands (2014), Q&A’s Intermunicipal cooperation, https://www.rijksoverheid.nl/onderwerpen/gemeenten/documenten/publicaties/2014/12/08/q-a-s-intergemeentelijke-samenwerking.

[158] Government of the Slovak Republic (1990), Law 369, https://www.slov-lex.sk/ezbierky/pravne-predpisy/SK/ZZ/1990/369/.

[186] Government of the United Kingdom (2011), Localism Act, https://www.legislation.gov.uk/ukpga/2011/20/pdfs/ukpga_20110020_en.pdf.

[184] Government of the United Kingdom (1972), Local Government Act 1972, https://www.legislation.gov.uk/ukpga/1972/70/contents.

[16] Horak M. and Doyon A. (2018), Metropolitan governance in Canada: lessons from Toronto and Vancouver, https://doi.org/IBSN 9781486307968.

[3] Hyslop S. et al. (2022), “Options for sharing services in Tasmanian local government. University of Tasmania.”, Review Background Research Paper No. 4.

[178] Kanton Argau (2019), Selbstständige öffentlich-rechtliche Gemeindeanstalten, https://www.ag.ch/media/kanton-aargau/dvi/dokumente/ga/aktuelles/gemeindetagungen/2019/201901-leitfaden-gemeindeanstalten.pdf.

[74] Kovacs, E. (2018), A települési önkormányzatok közötti együttműködések és koordinációs struktúrák elemzése, https://www.researchgate.net/publication/325679091_A_telepulesi_onkormanyzatok_kozotti_egyuttmukodesek_es_koordinacios_strukturak_elemzese.

[179] Kübler & Rochat (2018), “Fragmented Governance and Spatial Equity in Metropolitan Areas: The Role of Intergovernmental Cooperation and Revenue-Sharing”, Urban Affairs Review, Vol. Volume 55, Issue 5, https://doi.org/10.1177/1078087417753079.

[38] Kurian, M., P. Swianiewicz and F. Teles (2024), “Inter-municipal co-operation in the Western Balkans”, SIGMA Papers, No. 70, OECD Publishing, Paris, https://doi.org/10.1787/a78a01e6-en.

[105] Latvian Association of Local and Regional Governments (2026), Conference “Addressing local government staff shortages through IMC: EU practices and lessons”.

[82] Local Government Management Agency (2024), LGMA annual report 2023, https://www.lgma.ie/en/publications/annual-reports/lgma-annual-report-2023.pdf.

[37] LoGov (2021), Local Government in Croatia, https://doi.org/10.5281/zenodo.5716123.

[5] LOGOV/KDZ (2021), Local Government in Austria - Responses to Urban-Rural Challenges, https://www.kdz.eu/system/files/downloads/2021-12/LoGov_Austria_CR0.pdf.

[27] López Marín (2024), “Colombian Territorial Integration and Associativity: A Comparative Perspective from the internationa context”, Revista Ciudades, Estados y Política. Vol. 10(3), Vol. Vol. 10(3), pp. pp. 115-129.

[148] Łukaszczyk Z. (2018), “Shared services center – an opportunity for cost optimization and process standardization in local government units”, Scientific Journals of Organization and Management, https://yadda.icm.edu.pl/baztech/element/bwmeta1.element.baztech-f8ec22e6-fb27-43c6-86f9-295dd0cc38cf/c/ZNOiZ_2018_z.121_Lukaszczyk.pdf.

[95] M., K. (ed.) (2020), Inter-municipal Cooperation and Regional Waste Management in Japan, https://www.eria.org/uploads/media/Research-Project-Report/2020-12-Regional-Waste-Management-in-Asia/08_Ch.2-Inter-municipal-Cooperation-Japan.pdf.

[78] Magnússon M. Á. S. (2025), Iceland: Voluntary Coordination Among Municipalities—The Role of Amalgamations and Local Government Associations, https://link.springer.com/book/10.1007/978-3-031-83567-4.

[116] Maravalle Caldera Sánchez and González Pandiella (2024), Improving Housing and Urban Development Policies in Mexico, https://doi.org/10.1787/c2229c19-en.

[53] Ministry of Finance of the Republic of Estonia (2021), Administrative-Territorial Reform, https://www.fin.ee/en/administrative-territorial-reform.

[51] Ministry of Finance of the Republic of Estonia (2019), Administrative-Territorial Reform, https://www.agri.ee/sites/default/files/documents/2023-07/v%C3%A4ljaanne-2019-estonia-local-governments.pdf.

[187] Ministry of Housing Communities & Local Government (2025), Secretary of State’s Annual Report on English Devolution 2024-25, https://www.gov.uk/government/publications/annual-report-on-english-devolution-2024-to-2025/secretary-of-states-annual-report-on-english-devolution-2024-25.

[73] Ministry of Interior Greece (2024), Structure and Operation of Local and Regional Democracy, https://www.ypes.gr/wp-content/uploads/2024/06/STRUCTURE-OPERATION-LRD-ENGLISH-VERSION-2024.pdf.

[44] Ministry of Interior of Czechia (2025), Community of municipalities, https://spolecenstviobci.gov.cz/.

[161] Ministry of Interior of Slovakia (2025), Overview of joint municipal offices, https://www.minv.sk/?prehlad_SOU.

[9] Ministry of Regional Development and Public Work (1991), Local Government and Local Administration Act, https://www.mrrb.bg/en/local-government-and-local-administration-act/.

[145] Mirska A. (2025), Poland: The Complex Governance of Horizontal Coordination in the Context of EU Membership, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_13.

[43] Mon1tor (2024), Local Government, https://monitor.statnipokladna.gov.cz/uzemni-samosprava/dso?rad=t&obdobi=2412.

[2] Morgan, M. et al. (2024), “Inter-municipal cooperation and local government perspective on community health and wellbeing”, Australian Journal of Public Administration, Vol. 83/3, pp. 394-414, https://doi.org/10.1111/1467-8500.12597.

[106] Nathalie Behnke, B. (ed.) (2025), Bridging Levels of Governance: The Dynamics of Vertical and Horizontal Intergovernmental Relations in Latvia, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_10.

[86] Nathalie Behnke, B. (ed.) (2025), The Role and Challenges of Regional Clusters in Israel: Advancing Collaborative Governance Amidst Centralized Tensions, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_9.

[32] National Assembly of Costa Rica (2024), Bill 24080 on Mancomunidades Municipales, https://www.tevucr.org/sites/default/files/content/documents/Proyecto%20de%20ley%20Exp.%2024080%20%28con%20firmas%29.pdf.

[110] National Regional Development Council (2017), ithuanian Regional Policy White paper for harmonious and sustainable development 2017-2030, https://vrm.lrv.lt/uploads/vrm/documents/files/ENG_versija/Lithuanian%20Regional%20Policy%20%28White%20Paper%29.pdf.

[14] New Brunswick Canada (n/d), Local Governance Reform, https://www2.gnb.ca/content/gnb/en/corporate/promo/local-governance.html.

[96] Noda, Y. (2023), “Intermunicipal cooperation, integration forms, and vertical and horizontal effects in Japan”, https://doi.org/10.1111/puar.13569.

[191] Northern Ireland - Department for Communities (2025), Local Government Regulation, https://www.communities-ni.gov.uk/topics/local-government-housing-regulation.

[132] Norwegian Ministry of Local Government (2013), Local Goverment in Norway, https://www.regjeringen.no/globalassets/upload/kmd/komm/veiledninger_og_brosjyrer/local_government_in_norway_h-2313e.pdf.

[93] OECD (2025), Preparing for Demographic Change in Campania, Italy, OECD Publishing, Paris, https://doi.org/10.1787/071b9897-en.

[169] OECD (2025), Preparing for Demographic Change in Castilla y León, Spain, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/207044f7-en.

[156] OECD (2025), Preparing for Demographic Change in Nord-Vest, Romania,, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/21b50ace-en.

[159] OECD (2025), Preparing for Demographic Change in the Banská Bystrica Region, Slovak Republic, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/62ab1acb-en.

[85] OECD (2025), Redefining Spatial Planning and Development in Israel, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/89036c98-en.

[88] OECD (2025), Redefining Spatial Planning and Development in Israel, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/89036c98-en.

[139] OECD (2025), Regional Development Policy in Peru, OECD.

[100] OECD (2025), Shrinking smartly and sustainably in Korea, https://www.oecd.org/content/dam/oecd/en/publications/reports/2025/10/shrinking-smartly-and-sustainably-in-korea_4ff55dc0/161ae23e-en.pdf.

[154] OECD (2025), Shrinking smartly and sustainably in Portugal: Small and medium-sized cities in demographic transition, OECD Regional Development Papers, No. 167, OECD Publishing, Paris, https://doi.org/10.1787/666c29c4-en.

[52] OECD (2025), Strengthening Place-Based Regional Development Policy in Estonia, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/45e0cdc7-en.

[55] OECD (2025), Strengthening Place-Based Regional Development Policy in Estonia, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/45e0cdc7-en.

[59] OECD (2024), Enabling Inter-Municipal Shared Service Provision in Lithuania: Proposed Legal and Institutional Framework and Piloting Approach in Tauragė+ Functional Zone, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/f8ad6859-en.

[25] OECD (2024), OECD Economic Surveys: Colombia 2024, , OECD Publishing, Paris, https://doi.org/10.1787/a1a22cd6-en.

[49] OECD (2024), OECD Economic Surveys: Denmark 2024, OECD Publishing, Paris, https://doi.org/10.1787/d5c6f307-en.

[8] OECD (2024), OECD Territorial Reviews: Brussels-Capital Region, Belgium, OECD Territorial Reviews: Brussels-Capital Region, Belgium,, https://doi.org/10.1787/0552847b-en.

[188] OECD (2024), Regional Governance and Public Investment in Wales, United Kingdom: Moving Forward Together, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/e143e94d-en.

[190] OECD (2024), Regional Governance and Public Investment in Wales, United Kingdom: Moving Forward Together, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/e143e94d-en.

[35] OECD (2024), Towards Balanced Regional Development in Croatia: From Strategy Design to Implementation, OECD Multi-level Governance Studies, Paris, https://doi.org/10.1787/3c0779cf-en.

[31] OECD (2023), OECD Environmental Perfoamnce reviews: Costa Rica, https://doi.org/10.1787/ec94fd4e-en.

[119] OECD (2023), OECD Regional Outlook 2023: Mexico, OECD, https://www.oecd.org/en/publications/oecd-regional-outlook-2023-country-notes_be47635c-en/mexico_f74a2d50-en.html.

[109] OECD (2023), OECD Regional Outlook 2023: The Longstanding Geography of Inequalities (Lithuania country profile), OECD Publishing, Paris, https://doi.org/10.1787/92cd40a0-en.

[42] OECD (2023), Public governance review of Czechia - Towards a More Modern and Effective Public Administration - Chapter on regional and local governance, OECD Publishing, Paris, https://doi.org/10.1787/41fd9e5c-en.

[84] OECD (2023), Towards Balanced Regional Attractiveness in Ireland: Enhacing the Delivery of the National Planning Framework, OECD Publishing, https://www.oecd.org/content/dam/oecd/en/publications/reports/2023/12/towards-balanced-regional-attractiveness-in-ireland_c40e5d8f/3df116ad-en.pdf.

[101] OECD (2022), Adapting Regional Policy in Korea: Preparing Regions for Demographic Change, OECD Rural Studies, OECD Rural Studies, OECD Publishing, Paris,, https://doi.org/10.1787/6108b2a1-en.

[23] OECD (2022), National Urban Policy Review of Colombia, OECD Urban Studies, OECD Publishing, Paris,, https://doi.org/10.1787/9ca1caae-en.

[24] OECD (2022), Rural Policy Review of Colombia 2022, OECD Rural Studies, OECD Publishing,, https://doi.org/10.1787/c26abeb4-en.

[54] OECD (2022), Shrinking Smartly in Estonia: Preparing Regions for Demographic Change, OECD Rural Studies, OECD Publishing, Paris, https://doi.org/10.1787/77cfe25e-en.

[150] OECD (2022), Urban-Rural Linkages in Poland, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/94b5c782-en.

[87] OECD (2021), A Review of Local Government Finance in Israel: Reforming the Arnona System, OECD Multi-level Governance Studies, OECD Publishing,, https://doi.org/10.1787/a5bc4d25-en.

[151] OECD (2021), Better Governance, Planning and Services in Local Self-Governments in Poland, OECD Publishing, https://doi.org/10.1787/550c3ff5-en.

[10] OECD (2021), Decentralisation and Regionalisation in Bulgaria: Towards Balanced Regional Development, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/b5ab8109-en.

[12] OECD (2021), Decentralisation and Regionalisation in Bulgaria: Towards Balanced Regional Development, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/b5ab8109-en.

[99] OECD (2021), Perspectives on Decentralisation and Rural-Urban Linkages in Korea, OECD Rural Studies, OECD Publishing,, https://doi.org/10.1787/a3c685a7-en.

[153] OECD (2020), Decentralisation and Regionalisation in Portugal, https://doi.org/10.1787/fea62108-en.

[72] OECD (2020), Regional Policy for Greece Post-2020, OECD Territorial Reviews, OECD Territorial Reviews, OECD Publishing, Paris,, https://doi.org/10.1787/cedf09a5-en.

[189] OECD (2020), The Future of Regional Development and Public Investment in Wales, United Kingdom,, https://doi.org/10.1787/e6f5201d-en;.

[22] OECD (2019), Asymmetric decentralisation: Policy implications in Colombia, https://www.oecd.org/colombia/Asymmetric_decentralisation_Colombia.pdf.

[67] OECD (2019), OECD Territorial Review, Hambourg, metropolitan region, Germany, https://doi.org/10.1787/29afa27f-en.

[118] OECD (2019), OECD Territorial Reviews: Hidalgo, Mexico, OECD Territorial Reviews, OECD Publishing, Paris, https://doi.org/10.1787/9789264310391-en.

[19] OECD (2017), Making Decentralisation Work in Chile: Towards Stronger Municipalities, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/9789264279049-en.

[124] OECD (2017), Multi-level Governance Reforms: Overview of OECD Country Experiences, OECD Multi-level Governance Studies, OECD Publishing, Paris, https://doi.org/10.1787/9789264272866-en.

[21] OECD (2016), Making the Most of Public Investment in Colombia: Working Effectively across Levels of Government, OECD Multi-level Governance Studies, OECD Publishing, Paris,, https://doi.org/10.1787/9789264265288-en.

[143] OECD (2016), OECD Public Governance Reviews: Peru: Integrated Governance for Inclusive Growth, OECD Public Governance Reviews, OECD Publishing, Paris, https://doi.org/10.1787/9789264265172-en.

[97] OECD (2016), OECD Territorial Review of Japan, 2016, https://doi.org/10.1787/9789264250543-en.

[114] OECD (2015), OECD Territorial Review: Valle de México, OECD, https://doi.org/10.1787/9789264245174-en.

[103] OECD - International Transport Forum (2018), Policy directions establishing metropolitan transport authority for Korea’ Capital Region, https://www.itf-oecd.org/sites/default/files/docs/policy-directions-establishing-metropolitan-transport-authority-korea.pdf.

[6] OECD/UCLG (2022), World Observatory on Subnational Government Finance and investment - Country Profiles, https://www.sng-wofi.org/.

[140] Official Gazette Law No. 29029 (2007), Law of Municipal Mancomunidades, https://www.mef.gob.pe/es/normatividad/por-instrumento/leyes/6854-ley-n-29029-1/file (accessed on 9 September 2024).

[149] PAP Local Government Service (2019), Shared Service Centers – How They Work. Local Government Shared Service Centers – Two Years of Operation, https://samorzad.pap.pl/kategoria/archiwum/cuw-jak-dzialaja-samorzadowe-centra-uslug-wspolnych-dwa-lata-funkcjonowania.

[141] PCM (2024), Registry of Municipal and Regional Mancomunidades, https://www.gob.pe/institucion/pcm/colecciones/18047-mancomunidades-regionales-y-municipales (accessed on 15 October 2024).

[26] Pinzon & Moreno (2023), “Analysis of the municipal association in Colombia”, Revista Opera, https://doi.org/10.18601/16578651.n33.04.

[167] Podadera & Colomina (2025), Spain: Horizontal Coordination and the Autonomous Communities, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_16.

[138] Presidencia del Consejo de Ministro (2020), Registro de Mancomunidades Municipales, https://www.gob.pe/institucion/pcm/informes-publicaciones/437298-registro-de-mancomunidades-municipales.

[90] Puntillo, P. (2017), Inter-municipal cooperation in service delivery and governance: Insights from Italy, https://doi.org/10.1504/IJBGE.2017.088253.

[181] Republic of Türkiye (2005), Law on Municipalities, https://www.mevzuat.gov.tr/mevzuat?MevzuatNo=5393&MevzuatTur=1&MevzuatTertip=5.

[1] Sansom, G. (2019), The practice of Municipal Cooperation: Australia Perspectives and Comparisons with Canada, https://utoronto.scholaris.ca/server/api/core/bitstreams/490b1cd9-a75f-479b-b24d-7c617e79322d/content.

[133] Schakel Solvang & Stein (2025), Norway: Low Population Density as Challenge and Opportunity for Coordination, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_12.

[142] Secretario de Descentralización (2022), Programa de Apoyo a las Mancomunidades Municipales, https://cdn.www.gob.pe/uploads/document/file/3559600/Programa%20de%20Apoyo%20a%20las%20Mancomunidades%20Municipales.pdf?v=1665009581.

[40] Sedmihradská, L. (2018), “Inter-Municipal Cooperation in the Czech Republic: A Public Finance Perspective”, NISPAcee Journal of Public Administration and Policy, Vol. 11/2, pp. 153-170, https://doi.org/10.2478/nispa-2018-0017.

[182] Şemşit Eylemer & Erdoğan (2025), Türkiye: The Strong Role of Municipalities in Fostering Horizontal Coordination, https://link.springer.com/chapter/10.1007/978-3-031-83567-4_17.

[13] Spicer, Z. (2015), Cooperation and Capacity: Inter-mUnicipal Agreements in Canada, https://imfg.org/uploads/318/1623_imfg_no.19_spicer_online.pdf.

[175] Statskontoret (2023), Hand i hand – en analys av kommunal samverkan, https://www.statskontoret.se/siteassets/rapporter-pdf/2023/2023_5-utskriftsversion.pdf.

[157] Stoian C. Groza O. & Rusu A. (2024), “Assessing the viability of Romania’s newly established metropolitan areas”, Journal of Urban and Regional Analysis, pp. 16(1), 59-83, https://doi.org/10.37043/JURA.2024.16.1.3.

[18] SUBDERE (2026), Registro Único de Asociaciones Municipales con Personalidad Jurídica de Derecho Privado (Law 20.527), https://registroasociaciones.subdere.gov.cl/.

[174] Swedish Association of Local Authorities and Regions (SALAR) (2026), Conference “Addressing local government staff shortages through IMC: EU practices and lessons”.

[173] Swedish Association of Local Authorities and Regions (SALAR) (2024), Joint Committee, municipal association, https://skr.se/skr/demokratiledningstyrning/styraleda/driftformer/gemensamnamndkommunalforbund.1755.html.

[128] Tauranga Council (2020), Councils Controlled Organisation, https://www.tauranga.govt.nz/Portals/0/data/council/annual-reports/2020/files/council-controlled-organisations.pdf.

[126] The New Zealand Productivity Commission (2013), Primer on local government coordination Online appendix to the inquiry into local government regulatory performance, https://www.treasury.govt.nz/sites/default/files/2024-05/pc-inq-tblr-online-appendix-primer-on-local-government-coordination.pdf.

[46] Tisnov (2024), Community of Municipalities of Tišnov Region, https://www.tisnovsko-so.cz/seniori/o-nas/zakladni-informace/spolecenstvi-obci-tisnovsko/.

[168] Toscano Gil Francisco (2025), “Las mancomunidades de municipios de interés autonómico”, Anuario de Derecho Municipal, https://doi.org/0.37417/ADM/18-2024_1.02.

[33] University of Costa Rica (2024), Universidad de Costa Rica, Informe FCS-710-2024, https://www.fcs.ucr.ac.cr/images/DOCUMENTOS/CRITERIOS/2024/FCS-710-2024.pdf.

[121] Veenendaal, W. (2023), “Governing inter-municipal partnerships in the Netherlands”, Acta Politica, https://link.springer.com/article/10.1057/s41269-023-00295-6.