Convention on Mutual Administrative Assistance in Tax Matters


Last updated - July 2018

Antigua and Barbuda becomes the 125th jurisdiction to join the most powerful multilateral instrument against offshore tax evasion and avoidance

27/07/2018 - Her Excellency Karen-Mae Hill, High Commissioner of Antigua and Barbuda to the United Kingdom, signed the Convention in the presence of Deputy Secretary-General Masamichi Kono.

The Convention on Mutual Administrative Assistance in Tax Matters ("the Convention") was developed jointly by the OECD and the Council of Europe in 1988 and amended by Protocol in 2010. The Convention is the most comprehensive multilateral instrument available for all forms of tax co-operation to tackle tax evasion and avoidance, a top priority for all countries.


The Convention was amended to respond to the call of the G20 at its 2009 London Summit to align it to the international standard on exchange of information on request and to open it to all countries, in particular to ensure that developing countries could benefit from the new more transparent environment. The amended Convention was opened for signature on 1 June 2011.


Since 2009, the G20 has consistently encouraged countries to sign the Convention including most recently at the meeting of the G20 Finance Ministers and Central Bank Governors Meeting in February 2016 where the communique stated "We reiterate our call for all countries to join the Multilateral Convention on Mutual Administrative Assistance in Tax Matters [...]"


125 jurisdictions currently participate in the Convention, including 17 jurisdictions covered by territorial extension*. This represents a wide range of countries including all G20 countries, all BRIICS, all OECD countries, major financial centres and an increasing number of developing countries.


* In May 2018, the People’s Republic of China extended the territorial scope of the Convention to the Hong Kong and Macau Special Administrative Regions pursuant to Article 29. As such, The Convention will enter into force for both Hong Kong (China) and Macau (China) on 1 September 2018.


Discover the international state of play with an interactive map presenting key indicators and outcomes of the OECD work on international tax matters, with close to 150 countries and jurisdictions:


The amended Convention facilitates international co-operation for a better operation of national tax laws, while respecting the fundamental rights of taxpayers. The amended Convention provides for all possible forms of administrative co-operation between states in the assessment and collection of taxes, in particular with a view to combating tax avoidance and evasion. This co-operation ranges from exchange of information, including automatic exchanges, to the recovery of foreign tax claims. For more information on the amended Convention see the flyer (also available in Spanish) which provides a brief overview on the Convention. The amended Convention is also available in FrenchSpanish (unofficial translation) and Portuguese (unofficial translation).





The Convention on Mutual Administrative Assistance in Tax Matters (the "Convention"), by virtue of its Article 6, requires the Competent Authorities of the Parties to the Convention to mutually agree on the scope of the automatic exchange of information and the procedure to be complied with. Against that background, the Multilateral Competent Authority Agreement on the Exchange of CbC Reports (the "CbC MCAA"), for the automatic exchange of Country-by-Country Reports, and the Multilateral Competent Authority Agreement on Automatic Exchange of Financial Account Information (the "CRS MCAA"), for the automatic exchange of financial account information pursuant to the Common Reporting Standard, have been developed.