On 27 May 2010, in Paris, the Protocol amending the Multilateral Convention on Mutual Administrative Assistance in Tax Matters is concluded — the OECD/Council of Europe instrument that opens the convention to any state.

The original convention of 25 January 1988 (Strasbourg) facilitated tax-information exchange among OECD and CoE members. The 2010 Protocol aligns it with post-crisis transparency standards and makes it globally accessible at the invitation of the parties.

Protocol entry into force: 1 June 2011. The amended version drew over a hundred parties; the United States remains on the original convention without the Protocol.

MAC became the backbone of automatic exchange of tax information alongside the OECD CRS standards.

The depositaries are the Secretary General of the Council of Europe and the Secretary General of the OECD; official languages English and French.

The official text is published by the OECD and the Council of Europe.

The Protocol of 27 May 2010 remains the act that globalised the Convention on Mutual Administrative Assistance in Tax Matters.

Image: OECD / Paris; Wikimedia Commons. Cropped to 16:9.

Source consulted: Multilateral Convention on Mutual Administrative Assistance in Tax Matters. Treaty text: OECD / Council of Europe — Multilateral Convention on Mutual Administrative Assistance in Tax Matters.