The OECD has produced the Tax Administration Series (TAS), its comparative information series on tax administration, since 2004. Since that time the publication has grown in terms of its coverage, influence and importance and is now widely recognised as an authoritative source of information on tax administration around the globe.
The 2024 Tax Administration publication presents the results of the third to sixth round of the International Survey on Revenue Administration (ISORA) which were launched between 2020 and 2023. It would not have been possible without the direct support and help of a large number of people, particularly the staff in the 58 tax administrations that provided data and jurisdiction examples, reviewed content and responded to feedback and questions on the data and text that form the basis of the publication.
The authors of the publication were Paul Marsh, Fiona May and Oliver Petzold all from the OECD’s Forum on Tax Administration (FTA) Secretariat. Management and analysis of the ISORA data was undertaken by Oliver Petzold. The authors are thankful to Peter Green, Head of the FTA Secretariat, for his guidance and input during the drafting of this publication. They would also like to thank the work of the wider team at the FTA Secretariat, in particular Eunkyung Shin and Sonia Nicolas, and the OECD Centre for Tax Policy and Administration’s Communications team.
This edition of the TAS also benefits from a chapter on how tax administrations are estimating tax gaps authored by Sun Jae Kim and Alla Sytnik both from the Canada Revenue Agency. They would like to thank the members of the FTA’s Community of Interest on Tax Gaps for their input and valuable comments on this chapter.