The Multilateral Convention on Mutual Administrative Assistance in Tax Matters, sometimes abbreviated to MAC, MAAC or MAATM, is a convention to facilitate the entering into bilateral tax information exchange agreements between state parties. The convention was developed by the OECD and the Council of Europe and was open for signature to members of both organizations on 25 January 1988, and entered into force in 1995.
An amending protocol was concluded on 27 May 2010, which since coming into force became open to any state at the invitation of present state parties.
Ratifications The convention as well as the amending protocol entered into force upon the ratification of five members.
As of January 2025, one state (the United States) is a party to the original convention only, 26 states have ratified the original 1995 convention and the amending protocol, while 70 others are parties to the amended convention. The table below shows between whom the convention applies.
CategoryName Number of States Convention applies betweenother states of category O Original Convention 1 O + O&AP O&AP Original Convention and Amending Protocol 26 O + O&AP + AC (all states) AC Amended Convention 70 O&AP + AC
Country Ratification (original convention) Ratification (amending protocol, AP)/amended convention (AC) Comments (AC) Signed the amended convention on 10 October 2024 but has not ratified it. (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AC) (AC) (AC) (AP) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AP)Canada ratified the protocol, without ratifying the original convention (AC) (AC)Includes Hong Kong (2018) and Macau (2018) (AC) (AC) Signed the amended convention on 23 April 2025 but has not ratified it. (AP) (AP) (AC) (AP) Including Faroe Islands (since 2007) and Greenland (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AP) Signed the amended convention on 15 January 2026 but has not ratified it. Signed the amended convention on 3 July 2014 but has not ratified it. (AP) (AP) (AC) (AP) (AC) (AC) Signed the amended convention on 11 July 2022 but has not ratified it. (AP) (AP) (AC) (AC) (AC) (AC) (AP) (AC) (AP) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AP) Signed the amended convention on 7 July 2022 but has not ratified it. (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AP) (AC) (AC) (AC) (AC) (AC) (AC) (AP) includes Caribbean Netherlands, Aruba, Curacao, and Sint Maarten (AC) includes Cook Islands and Niue. (AC) (AC) (AP) (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AP) (AC) (AC) (AP) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AC) (AP) (AC) (AP) (AP) (AP) (AC) (AC) Signed the amended convention on 30 January 2020 but has not ratified it. (AC) (AC) (AC) (AC) (AP) (AC) (AP) Also extended to Anguilla, Bermuda, British Virgin Islands, Cayman Islands, Gibraltar, Guernsey, Isle of Man, Jersey, Montserrat, and Turks and Caicos Islands Including all territories under its jurisdiction; has signed but not ratified the amending protocol (AC) (AC) (AC)
See also Tax information exchange agreements International taxation
References
External links Convention text - Centre for Tax Policy and Administration Protocol text - Protocol amending the Convention on Mutual Administrative Assistance in Tax Matters Signatures and ratifications