Tax Administration 2025

1. Introduction

Abstract

This chapter provides an overview of the content of the 2025 edition of the OECD’s Tax Administration Series.

In 2017, the seventh edition of the TAS described the changing face of tax administration noting how new technologies, analytical tools and a significant increase in the data tax administrations had access to was allowing them to rethink their operational models, providing new opportunities to improve services, enhance compliance and reduce burdens. (OECD, 2017[1])

The embedding of technology into tax administration has continued at pace since then, including the rise of AI, and, in 2020, the OECD formulated its vision of a digitally transformed tax administration, referred to as Tax Administration 3.0 (OECD, 2020[2]). This future of tax administration has inspired the strategic plans of many tax administrations, and some are well underway with their digital transformation.

Box 1.1. Denmark – Strategic framework for digital transformation

The Danish Tax Agency (DTA) has developed a strategic framework for digital transformation, to keep up with wider technological advances in society and create future-proof solutions, strengthening the public’s trust in the tax administration.

The framework consists of three main deliverables:

• A vision: The vision reflects where the administration wants to get to in a specific business area over the next fifteen years.

• Business and Information Technology (IT) architecture: The business and IT architecture is the “translation” of the vision into an architectural design that includes capabilities, applications and technologies. By using business and IT architecture methods, the DTA is able to identify initiatives that will enable the organisation to reach its target state.

• Roadmap: The roadmap will be composed of all the identified initiatives being implemented to achieve the vision. These can be split into the short, medium and long-term. Furthermore, the roadmap will also enable the DTA to track the effectiveness of each initiative.

The ambition is to apply the strategic framework to every domain in the domain landscape. The landscape consists of fourteen business domains, where each domain includes different core tasks and deliverables. Applying the framework to each business domain allows officials to better understand the DTA, and to strategically follow the development of each domain within the landscape. Last year, the framework was applied on four business domains:

• Corporate taxation

• Equity shares, dividends, and pensions

• Value added tax

• Preliminary income assessment and tax assessment notice.

Source: Denmark (2025).

To obtain insights as to how tax administration has evolved over the past years, this edition of the TAS compares in several instances 2023 fiscal year data collected through the 2024 ISORA survey, with the historical 2014 data.

While this 10-year perspective, comparing ISORA data for fiscal years 2014 and 2023, needs to be considered with caution due to changing circumstances of tax administration, such as new responsibilities, it nevertheless allows high level insights as to the evolution of tax administration.

As previously, alongside the ISORA data, the tax administrations covered in this edition of the TAS were also invited to provide examples of innovative practices that they are undertaking to help achieve their objectives. They have provided a rich source of over 80 examples, covering a wide range of topics. While these examples do not form a basis for comparison across tax administrations in the same way as the ISORA data points can in some circumstances, they do add more colour to the data and give pointers to the strategic direction of travel of tax administrations globally, as is evident by the large number of AI related examples provided.

Furthermore, this edition of the TAS continues to use information from the ITTI database (OECD et al., 2025[3]). ITTI collects data on the digital transformation and digitalisation work of tax administrations from across the globe, and this rich source of data can provide further insight into the developments taking place in tax administration, facilitating mutual learning and collaboration.

Structure of the 2025 edition

Regardless of the country context that a tax administration operates in, the core objective remains the same, namely the timely and accurate collection of tax revenues to fund public services. Chapter 2 explores this topic in more detail and provides statistics on the range and value of taxes that administrations are responsible for.

Central to achieving their objective is the work of tax administrations to ensure that all relevant taxpayers are registered and can be identified, as necessary, both quickly and securely. Chapter 3 sets out the work of tax administrations in this field, including the impact of digital transformation on identity management.

Chapter 4 looks at the tax assessment function, including all activities related to processing tax returns and payments. This chapter also examines the use of e-channels for filing and paying, and outlines administrations’ efforts to provide pre-filled returns, as well as the levels of on-time return filing and payment.

Providing services aligned with taxpayer expectations and supporting them in meeting their tax obligations, is essential for high levels of voluntary compliance. Chapter 5 highlights the work of tax administrations in this space, including how they are encouraging “self-service” by taxpayers and the increasing role that artificial intelligence plays in service provision.

Managing compliance is the core topic of Chapter 6 and it explores how tax administrations are identifying compliance risks, often through the use of data and new technology tools. This chapter further comments on the performance of tax administrations in the delivery of compliance actions undertaken.

The efficient collection of outstanding taxes is essential to maintaining high levels of voluntary compliance and citizens’ confidence in the overall tax system. Chapter 7 looks at how tax administrations manage this and examines the features of a modern tax debt collection function.

However, inevitably, disputes between taxpayers and tax administrations do arise, and Chapter 8 considers those processes that safeguard taxpayer rights and ensure appropriate checks and balances exist on the exercising of tax powers by administrations.

Underpinning all this work are the resources that are available to tax administrations. Chapter 9 provides information on the resources that tax administrations have at their disposal and describes how working practices are changing.

Finally, last year’s publication contained several additional aspects of tax administration, that were covered in the extended ISORA 2023 survey that is run every 5 years. The 2024 edition of this series remains the most recent source of information on that extended survey. (OECD, 2024[4])

References

[4] OECD (2024), Tax Administration 2024: Comparative Information on OECD and other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/2d5fba9c-en.

[2] OECD (2020), Tax Administration 3.0: The Digital Transformation of Tax Administration, OECD Publishing, Paris, https://doi.org/10.1787/ca274cc5-en.

[1] OECD (2017), Tax Administration 2017: Comparative Information on OECD and Other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/tax_admin-2017-en.

[3] OECD et al. (2025), Inventory of Tax Technology Initiatives, https://www.oecd.org/content/oecd/en/data/datasets/inventory-of-tax-technology-initiatives.html (accessed on 1 October 2025).