What is ISORA?

International Survey on Revenue Administration (ISORA) collects comparable data on tax administration from administrations around the world using questions and definitions agreed by four international organizations:

  • Inter-American Center of Tax Administration (CIAT);
  • International Monetary Fund (IMF);
  • Intra-European Organisation of Tax Administrations (IOTA); and
  • Organisation for Economic Co-operation and Development (OECD).


In 2016, these four organisations signed a Memorandum of Understanding governing the administration and management of this worldwide survey. The Asian Development Bank (ADB) supported many of the participants in ISORA 2018, 2020, 2021 and 2022.


ISORA uses an on-line data collection platform (the Revenue Administration Fiscal Information Tool – RA-FIT) developed and administered by the IMF.

ISORA development
  • ISORA 2016 covered fiscal years 2014 and 2015, and the data provided by 135 tax administrations was included in the final database.
  • ISORA 2018 covered fiscal years 2016 and 2017, and data on 159 administrations was included in the final database.
  • ISORA 2020 covered fiscal years 2018-2019 and included the data of 156 participants.
  • ISORA 2021 covering fiscal year 2020 collected the data from 165 participants.
  • ISORA 2022 covering fiscal year 2021 – is in progress.
  • ISORA 2023 – PERIODIC SURVEY (every 4 years).


Following the participants survey conducted in 2018, the ISORA partners agreed that there was a need for a major revision of ISORA, to enhance data quality while reducing the burden on administrations in completing the survey. The survey was split into two components:

  • An annual questionnaire including questions to which the responses are more likely to change every year.  ISORA 2020 used the annual questionnaire, for the first time.
  • A periodic questionnaire including questions where responses are less likely to change between surveys. The periodic survey will commence in 2023 and will ask for data related to fiscal year 2022.  Current plans are to conduct the periodic questionnaire every 4 years.
ISORA data

Annual surveys collect data in the following areas:

Data is publicly available at: Graphical user interface, text, applicationDescription automatically generated

Any official of IOTA member tax administration can register and use the portal. Each participating tax administration has assigned an ISORA coordinator for the data collection process.


If you have any questions regarding ISORA, please contact:
Oksana Stepanenko, International Taxation Expert,[email protected]