Tax Administration 2025

Annex A. Overview of the ISORA data tables

Annex A contains an overview of the ISORA data tables that hold the latest available annual and periodic ISORA data for fiscal years 2018 to 2023, and that are published on the ISORA data portal (https://isoradata.org, accessed on 1 October 2025).

The data tables hold the data for the more than 175 jurisdictions that have completed at least one of the last five rounds of ISORA which were launched between September 2020 and September 2024. They are grouped into three sets:

• Review tables (see Table A A.1.) contain the ISORA data collected through the annual survey part. Those are the more than hundred tables starting with “A”:

• Derived tables (see Table A A.2.) contain indicators derived from the raw data submitted via the annual ISORA survey part. Those are 49 tables starting with “D”. The formulae and data points used for calculating the indicators are shown below each of these tables.

• Periodic tables (see Table A A.3.) hold the data from the periodic part of the 2023 ISORA survey. Those 52 tables start with “B”.

Using the ISORA data in those tables, the Tax Administration 2024 publication examines various aspects of tax systems and their administration in 58 OECD and non-OECD jurisdictions. (See Annex B for the list of tax administrations covered by this publication.)

Table A A.1. Overview of the ISORA data tables: Review tables

ISORA survey form	Table name
Form A: Tax types	Table A.0 Participation of tax administrations in ISORA
	Table A.1 Revenue types for which the administration has responsibility: Income tax and taxes on goods and services
	Table A.2 Revenue types for which the administration has responsibility: Other taxes
	Table A.3 Revenue types for which the administration has responsibility: Other taxes (continued), SSC and non-tax revenue
	Table A.4 Employer withholding taxes and combined tax and customs administrations
Form B: Revenue	Table A.5 Net revenue collected by the tax administration: Total
	Table A.6 Net revenue collected by the tax administration by tax type: Personal income tax
	Table A.7 Net revenue collected by the tax administration by tax type: Corporate income tax
	Table A.8 Net revenue collected by the tax administration by tax type: Value added taxes
	Table A.9 Net revenue collected by the tax administration by tax type: Excises (domestic)
	Table A.10 Net revenue collected by the tax administration by tax type: Other taxes
	Table A.11 Net revenue collected by the tax administration: Social security contributions
	Table A.12 Net revenue collected by the tax administration: Non-tax revenues
	Table A.13 Composition of value added taxes collected by the tax administration: Gross domestic
	Table A.14 Composition of value added taxes collected by the tax administration: Gross import, even where collected by customs
	Table A.15 Composition of value added tax collected by the tax administration: Refunds
Form C: Expenditure and FTE resources	Table A.16 Tax administration expenditures: Operating and salary expenditure
	Table A.17 Tax administration ICT expenditure and capital expenditure
	Table A.17A FTEs for joint tax and customs administrations
	Table A.17B Expenditures for joint tax and customs administrations
	Table A.18 Total FTEs of the tax administration and FTEs of the tax administration by function: Registration and services
	Table A.19 Number of FTEs by function: Audit and debt collection
	Table A.20 Number of FTEs by function: Disputes and HR
	Table A.21 Number of FTEs by function: ICT and all other functions; Percentage of FTEs working on headquarter functions
Form D: Human resource information	Table A.22 Staff metrics: Staff strength levels at start of FY and departures
	Table A.23 Staff metrics: Staff strength levels at end of FY and recruitments
	Table A.24 Staff metrics: Gender information
	Table A.25 Staff metrics: Gender distribution - Female
	Table A.26 Staff metrics: Gender distribution - Male
	Table A.27 Staff metrics: Gender distribution - Other gender
	Table A.28 Staff metrics: Academic qualifications
	Table A.29 Staff metrics: Age distribution below 35 years
	Table A.30 Staff metrics: Age distribution 35 to 54 years
	Table A.31 Staff metrics: Age distribution 55 years and above
	Table A.32 Staff metrics: Length of service below 10 years
	Table A.33 Staff metrics: Length of service 10 years and above
Form E: Taxpayer segments	Table A.34 Large taxpayer office / program: Existence and revenue collected
	Table A.35 Large taxpayer office / program: Functions - Registration, return and payment processing, and services
	Table A.36 Large taxpayer office / program: Functions - Audit, debt collection, dispute resolution
	Table A.37 Large taxpayer office / program: Staff
	Table A.38 Large taxpayer office / program: Taxpayers
	Table A.39 Large taxpayer office / program: Audits
	Table A.40 High net wealth individuals (HNWIs) office / program: Existence and revenue collected
Form F: Operational metrics	Table A.41 Number of taxpayers by tax type: Corporate income tax
	Table A.42 Number of taxpayers by tax type: Personal income tax
	Table A.43 Number of taxpayers by tax type: Employers that withhold tax from employees
	Table A.44 Number of taxpayers by tax type: Value added tax
	Table A.45 Number of taxpayers by tax type: Excise
	Table A.46 Return filing: Expected and received returns - Corporate income tax
	Table A.47 Return filing: Returns received on time - Corporate income tax
	Table A.48 Return receipt channels: Paper and electronic, not prefilled - Corporate income tax
	Table A.49A Return receipt channels: Electronic returns, prefilled - Corporate income tax
	Table A.49B Return receipt channels: Electronic returns, prefilled - Corporate income tax
	Table A.50 Return filing: Expected and received returns - Personal income tax
	Table A.51 Return filing: Returns received on time - Personal income tax
	Table A.52 Return receipt channels: Paper and electronic, not prefilled - Personal income tax
	Table A.53A Return receipt channels: Electronic returns, prefilled - Personal income tax
	Table A.53B Return receipt channels: Electronic returns, prefilled - Personal income tax
	Table A.54 Return filing: Expected and received returns - Employers that withhold tax from employees
	Table A.55 Return filing: Returns received on time - Employers that withhold tax from employees
	Table A.56 Return receipt channels: Paper and electronic, not prefilled - Employers that withhold tax from employees
	Table A.57A Return receipt channels: Electronic returns, prefilled - Employers that withhold tax from employees
	Table A.57B Return receipt channels: Electronic returns, prefilled - Employers that withhold tax from employees
	Table A.58 Personal income tax withholding: Requirements and total withholdings
	Table A.59 Return filing: Expected and received returns - Value added tax
	Table A.60 Return filing: Returns received on time - Value added tax
	Table A.61 Return receipt channels: Paper and electronic, not prefilled - Value added tax
	Table A.62A Return receipt channels: Electronic returns, prefilled - Value added tax
	Table A.62B Return receipt channels: Electronic returns, prefilled - Value added tax
	Table A.63 Payments due and received: Corporate income tax
	Table A.64 Payments received on time: Corporate income tax
	Table A.65 Payments due and received: Personal income tax
	Table A.66 Payments received on time: Personal income tax
	Table A.67 Payments due and received: Employers that withhold tax from employees
	Table A.68 Payments received on time: Employers that withhold tax from employees
	Table A.69 Payments due and received: Value added tax
	Table A.70 Payments received on time: Value added tax
	Table A.71 Electronic payments
	Table A.72 Treatment of most approved VAT refunds
	Table A.73 Value of all VAT ‘credits’
	Table A.74 Closing stock of arrears: Total and non-collectable
	Table A.75 Closing stock of arrears relating to state owned enterprises: Total and non-collectable
	Table A.76 Closing stock of arrears by tax type: Corporate income tax
	Table A.77 Closing stock of arrears by tax type: Personal income tax
	Table A.78 Closing stock of arrears by tax type: Tax withheld by employers from employees
	Table A.79 Closing stock of arrears by tax type: Value added tax
	Table A.80 Verification / audit activity: All audits (excluding electronic compliance checks)
	Table A.81 Verification / audit activity: Value of additional assessments raised - All audits (excluding electronic compliance checks)
	Table A.82 Verification / audit activity: Value of additional assessments raised - Corporate income tax
	Table A.83 Verification / audit activity: Value of additional assessments raised - Personal income tax
	Table A.84 Verification / audit activity: Value of additional assessments raised - Tax withheld by employers from employees
	Table A.85 Verification / audit activity: Value of additional assessments raised - Value added tax
	Table A.86 Verification / audit activity: Electronic compliance checks
	Table A.87 Tax crime investigations: Role of the administration
	Table A.88 Tax crime investigations: Number of cases
	Table A.89 Dispute resolution: Review mechanisms
	Table A.90 Dispute resolution: Review procedure
	Table A.91 Dispute resolution: Number of cases - Tax cases under internal procedures
	Table A.92 Dispute resolution: Number of cases - Tax cases under independent review by external bodies
	Table A.93 Dispute resolution: Number of cases - Tax cases under independent review by a higher appellate court
Form G: Taxpayer and other stakeholder interactions	Table A.94 Registration channels: Online, Telephone, Email
	Table A.95 Registration channels: Mail / post, In-person, other
	Table A.96 Incoming service contacts: Track keeping and number of contacts by channel - Online and digital assistance
	Table A.97 Incoming service contacts: Number of contacts by channel - Telephone call and e-mail
	Table A.98 Incoming service contacts: Number of contacts by channel - Mail / post and in-person
	Table A.99 Pre-fill of PIT returns: Income information - Personal information, and wage and salary
	Table A.100 Pre-fill of PIT returns: Income information - Pension, interest, and dividends
	Table A.101 Pre-fill of PIT returns: Income information - Capital gains / losses, and other income
	Table A.102 Pre-fill of PIT returns: Expense information - Donations, school and university fees, and childcare expenses
	Table A.103 Pre-fill of PIT returns: Expense information - Insurance premiums, health and medical expenses, and retirement contributions
	Table A.104 Pre-fill of PIT returns: Expense information - Interest, and other expenses
	Table A.105 Compliance approaches: Electronic invoicing
	Table A.106 Compliance approaches: Devices that register transactions
	Table A.107 Cooperative compliance approaches
	Table A.108 Innovative technologies: Implementation and usage - Blockchain, artificial intelligence, and cloud computing
	Table A.109 Innovative technologies: Implementation and usage - Data science, robotic process automation, and APIs
	Table A.110 Innovative technologies: Implementation and usage - Whole-of-government identification, digital authentication technology, and virtual assistants

Source: ADB, CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, https://data.imf.org/-/media/iData/External-Storage/Documents/4909A00B31A446CCBF1ABF16D53B0487/en/ISORA-2024-Review-Tables-FY2018-2023.xlsm (accessed on 1 October 2025).

Table A A.2. Overview of the ISORA data tables: Derived tables

Indicator grouping	Table name
Revenue	Table D.1 Revenue related ratios: Revenue to total government revenue and GDP
	Table D.2 Revenue related ratios: Tax to GDP and non-tax revenue to total revenue
	Table D.3 Tax structure and SSC proportions: PIT, CIT and VAT
	Table D.4 Tax structure and SSC proportions: Excises, Other taxes and SSC
Resources	Table D.5 Resource ratios: Full-time equivalent (FTE)
	Table D.6 Resource ratios: Cost
Staff	Table D.7 Staff allocation by location and function: Registration, services, processing, and audit and verification
	Table D.8 Staff allocation by function: Debt collection, dispute management, and HR management
	Table D.9 Staff allocation by function: ICT support and all other functions
	Table D.10 Staff dynamics
	Table D.11 Academic qualifications
	Table D.12 Staff age distribution: Staff below 45 years
	Table D.13 Staff age distribution: Staff 45 years and above
	Table D.14 Length of service: Less than 10 years
	Table D.15 Length of service: 10 years or more
	Table D.16 Gender distribution
Segmentation	Table D.17 Large taxpayer office / program ratios: Full-time equivalents (FTEs)
	Table D.18 Large taxpayer office / program ratios: Corporate taxpayers, additional assessments raised, and net revenue administered
Registration	Table D.19 Registration of personal income taxpayers
	Table D.20 Percentage inactive taxpayers on registers: CIT, PIT and PAYE
	Table D.21 Percentage inactive taxpayers on registers: VAT and Excise
Return filing	Table D.22 Rate of returns received on-time: CIT
	Table D.23 Rate of returns received on-time: PIT
	Table D.24 Rate of returns received on-time: PAYE
	Table D.25 Rate of returns received on-time: VAT
	Table D.26 Electronic filing: CIT and PIT
	Table D.27 Electronic filing: PAYE and VAT
	Table D.28 Proportion of returns by channel: CIT - Paper and electronic, not prefilled
	Table D.29 Proportion of returns by channel: CIT - Electronic, prefilled
	Table D.30 Proportion of returns by channel: PIT - Paper and electronic, not prefilled
	Table D.31 Proportion of returns by channel: PIT - Electronic, prefilled
	Table D.32 Proportion of returns by channel: PAYE - Paper and electronic, not prefilled
	Table D.33 Proportion of returns by channel: PAYE - Electronic, prefilled
	Table D.34 Proportion of returns by channel: VAT - Paper and electronic, not prefilled
	Table D.35 Proportion of returns by channel: VAT - Electronic, prefilled
Payment	Table D.36 Rate of payments received on-time: CIT
	Table D.37 Rate of payments received on-time: PIT
	Table D.38 Rate of payments received on-time: PAYE
	Table D.39 Rate of payments received on-time: VAT
	Table D.40 Electronic payment proportions and third party withholding
Arrears	Table D.41 Arrears ratios: Closing stock and collectable arrears
	Table D.42 Arrears ratios: Year-on-year change
	Table D.43 Arrears ratios relating to state owned enterprises: Closing stock and collectable arrears
	Table D.44 Arrears in relation to collection by tax type: CIT and PIT
	Table D.45 Arrears in relation to collection by tax type: PAYE and VAT
Audit	Table D.46 Audit ratios: Hit rate and additional assessments raised
	Table D.47 Audit ratios: Additional assessments raised by tax type - CIT and PIT
	Table D.48 Audit ratios: Additional assessments raised by tax type - PAYE and VAT
Disputes	Table D.49 Administrative review cases and litigation

Source: ADB, CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, https://data.imf.org/-/media/iData/External-Storage/Documents/A5265B1B25CC438283ED26CF2E0F8FA4/en/ISORA-2024-Derived-Tables-FY2018-2023.xlsm (accessed on 1 October 2025).

Table A A.3. Overview of the ISORA data tables: Periodic tables

ISORA survey form	Table name
Form C-P: Institutional arrangements, governance and management practices	Table B.1 Institutional framework and management autonomy
	Table B.2 Roles in addition to revenue collection
	Table B.3 Selected governance practices: Audit, code of conduct and integrity
	Table B.4 Selected governance practices: Plans, reports and standards; and organizational chart
	Table B.5 Structural reforms: Implementation and nature
	Table B.6 Structural reforms: Main drivers
Form D-P: Human resource management	Table B.7 Human resource authority
	Table B.8 Remuneration and performance management
	Table B.9 HR management approach: Staff surveys
	Table B.10 HR management approach: Strategy / multi-year work force plan and training strategy
	Table B.11 HR management approach: Support for new staff and staffing plan
	Table B.12 HR management approach: staffing plan and flexible working arrangements
	Table B.13 HR management approach: Leadership development, time reporting, diversity policy
	Table B.14 Capability needs assessment
	Table B.15 Specialist skills
Form E-P: Segmentation and compliance risk management	Table B.16 Large taxpayer office / program: Main criteria
	Table B.17 High net wealth individuals (HNWIs) office / program: Main criteria
	Table B.18 High net wealth individuals (HNWIs) office / program: Functions, staff and taxpayers
	Table B.19 Small taxpayers
	Table B.20 Compliance risk management: Strategy
	Table B.21 Compliance risk management: Gender-disaggregated data
	Table B.22 Compliance risk management: Characterization of challenges related to international tax issues
	Table B.23 Compliance risk management: Staff related to international tax issues
	Table B.24 Compliance risk management: Tax gap
	Table B.25 Compliance risk management: Compliance intervention framework
	Table B.26 Compliance risk management: Interventions before return filing
	Table B.27 Compliance risk management: Interventions after return filing, and measurement of intervention effectiveness
	Table B.28 Compliance risk management: Post-filing enforcement actions
	Table B.29 Compliance risk management: Enforcement effectiveness indicators
Form F-P: Tax operations	Table B.30 Taxpayer gender recorded; and mandatory electronic filing and payment
	Table B.31 Tax arrears collection powers and their usage - Part 1
	Table B.32 Tax arrears collection powers and their usage - Part 2
	Table B.33 Tax arrears collection powers and their usage - Part 3
	Table B.34 Tax arrears collection powers and their usage - Part 4
	Table B.35 Voluntary disclosures; and verification / audit activity: Automated compliance checks
	Table B.36 Verification / audit activity: Random audits
	Table B.37 Verification / audit activity: Selection processes / criteria
	Table B.38 Administrative sanctions for taxpayer non-disclosure: Application and selected features
Form G-P: Engagement with stakeholders: taxpayers, information providers and others	Table B.39 Service channels: Statistics about service channel usage
	Table B.40 Service channels: Features of the service approach
	Table B.41 Service channels: Online services - Part 1
	Table B.42 Service channels: Online services - Part 2
	Table B.43 Taxpayer rights: Documentation
	Table B.44 Taxpayer rights: Complaints mechanisms
	Table B.45 Satisfaction surveys
	Table B.46 Gender-based analysis of taxpayer satisfaction, and service and assistance strategy
	Table B.47 Taxpayer education
	Table B.48 Rulings on the application of tax laws
	Table B.49 Withholding at source
	Table B.50 Reporting of payment details
	Table B.51 Third-party data
	Table B.52 Taxpayer compliance burden

Source: ADB, CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, https://data.imf.org/-/media/iData/External-Storage/Documents/AF9FEB8CB9C846379C9131E8289B1DF4/en/ISORA-2023-Periodic-tables.xlsx (accessed on 1 October 2025).