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.

The Convention facilitates international co-operation for a better operation of national tax laws, while respecting the fundamental rights of taxpayers. It provides for all possible forms of administrative co-operation between states in the assessment and collection of taxes. This co-operation ranges from exchange of information, including automatic exchanges, to the recovery of foreign tax claims.

Since 2009, the G20 has consistently encouraged countries to sign the Convention including most recently at the G20 summit in Buenos Aires in 2018 where the communique stated "All jurisdictions should sign and ratify the multilateral Convention on Mutual Administrative Assistance in Tax Matters."

The text of the amended Convention is available in English, French, German (unofficial translation), Spanish (unofficial translation) and Portuguese (unofficial translation).

147 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.

• See chart of participating jurisdictions

^{22/03/2023 - Deputy Secretary-General Mr. Yoshiki Takeuchi and Mr. Cao Anh Tuan – Deputy Minister of Finance of Vietnam}

In accordance with Article 24(3) and (4) of the Convention, the Co-ordinating Body is responsible for monitoring the implementation and development of the Convention, including:

• acting as a forum to increase international cooperation in tax matters;
• recommending revisions or amendments to the Convention;
• furnishing opinions on the interpretation of provisions of the Convention;
• serving as the body through which decisions are taken to invite States to become Parties to the Convention; and
• co-ordinating the implementation of Multilateral Competent Authority Agreements.

The Co-ordinating Body is composed of representatives of the competent authorities of the Parties to the Convention and includes the competent authorities of territories to which the Convention applies. The Co-ordinating Body is led by the Chair and three Vice-Chairs. The current officers are:

• John Nash (New Zealand) – Chair
• Nancy Tremblay (Canada) – Vice-Chair
• Wayne Brown (Bermuda) – Vice-Chair
• United Kingdom – Vice-Chair

The Co-ordinating Body is assisted in its tasks by the Secretariat of the OECD.