Good revenue administration is a vital contributor to good government. This book examines the experience of 11 countries in integrating revenue administration to optimize effectiveness and enhance efficiency over the past three decades, either by merging tax and customs administration or unifying collection of tax and social contributions.

In order to minimize the need for taxpayers to respond to multiple revenue agencies, some countries have integrated their revenue administrations, either by merging tax and customs administration, or unifying collection of tax and social contributions. This book examines the experience of 11 countries in doing so. Their experiences indicate that integrating collection entails modernizing the revenue administration and reducing contact between the tax office and taxpayers, thanks to the extensive use of ICT.

This report is the ninth edition of the OECD's Tax Administration Series. It provides internationally comparative data on aspects of tax systems and their administration in 59 advanced and emerging economies.

Building on previous FAD work in the tax administration field, this paper defines broad criteria for diagnosing the problems in a country’s tax administration and formulating an appropriate reform strategy. To be effective, this strategy should be based on the size of the tax gap and the country’s particular circumstances. This paper discusses some guiding principles which have provided the basis for successful reforms, including: reducing the tax system’s complexity, encouraging taxpayers’ voluntary compliance, differentiating the treatment of taxpayers by their revenue potential, and ensuring the reform’s effective management. Also discussed are specific bottlenecks that hinder the effectiveness of the tax administration’s operations.

The Fund has long played a lead role in supporting developing countries’ efforts to improve their revenue mobilization. This paper draws on that experience to review issues and good practice, and to assess prospects in this key area.

This paper addresses core challenges that all tax administrations face in dealing with noncompliance—which are now receiving renewed attention. Long a priority in developing countries, assuring strong compliance has acquired greater priority in countries facing intensified revenue needs, and is critical for fairness and statebuilding. Series: Policy Papers

This paper sets out a framework for analyzing optimal interventions by a tax administration, one that parallels and can be closely integrated with established frameworks for thinking about optimal tax policy. Its key contribution is the development of a summary measure of the impact of administrative interventions—the “enforcement elasticity of tax revenue”—that is a sufficient statistic for the behavioral response to such interventions, much as the elasticity of taxable income serves as a sufficient statistic for the response to tax rates. Amongst the applications are characterizations of the optimal balance between policy and administrative measures, and of the optimal compliance gap.

This technical note is the first of three addressing information technology (IT) themes and issues relevant to tax administrations. This note focuses on the use of technology in tax administrations and how to develop an information technology strategic plan (ITSP). It is intended for tax administrations that are largely manual or have outdated legacy IT systems. The second note addresses how to select an IT system for core tax administrations functions. And the third note covers implementation of a commercial-off-the-shelf (COTS) system. These technical notes are primarily for use by tax administrations that have no technology to manage their core tax processes, or their technology is limited and outdated. These notes focus on core tax functions and do not address other business systems (e.g., payroll, finance, document, and asset management systems).

It is generally difficult to measure revenue not collected due to noncompliance, but a growing number of countries now regularly produce and publish estimated revenue losses. Good tax gap analysis enables the detection of changes in taxpayer behavior by consistent estimates over time. This Technical Note sets out the theoretical concepts for personal income tax (PIT) gap estimation, the different measurement approaches available, and their implications for the scope and presentation of statistics. The note also focuses on the practical steps for measuring the PIT gap by establishing a random audit program to collect data, and how to scale findings from the sample to the population.

This edition of the series provides internationally comparative data on aspects of tax systems and their administration in 55 advanced and emerging economies. It covers all jurisdictions that were members of the OECD's Forum on Tax Administration (FTA) at the launch of the 2016 tax administration survey. In addition, it includes information on Peru, that became a member of the FTA in March 2017; the non-FTA jurisdictions that are members of the European Union (i.e. Bulgaria, Croatia, Cyprus, Malta, and Romania); as well as Morocco (which increases the reports' geographical coverage).