OECD Updates Signatory List for Addendum to the CRS Multilateral Competent Authority Agreement

Overview of the Multilateral Competent Authority Agreement

International cooperation in financial account oversight relies on multilateral legal frameworks designed to standardize cross-border communication among sovereign tax authorities ^[1]. A central pillar of this architecture is the Multilateral Competent Authority Agreement on Automatic Exchange of Financial Account Information, commonly referred to as the CRS MCAA ^[1]. Under this framework, Competent Authorities establish formal relationships to improve international tax compliance through mutual assistance in tax matters and routine automatic exchanges of information ^[1].

The foundational premise of the CRS MCAA is that participating jurisdictions enact domestic statutory provisions aligned with the Common Reporting Standard (CRS) ^[1]. The agreement specifies that the domestic laws of participating jurisdictions are subject to periodic amendments to incorporate updates made to the CRS ^[1]. Once these legislative changes are formally enacted by a jurisdiction, the CRS MCAA is deemed to refer to the updated version of the standard with respect to that specific jurisdiction ^[1].

The 2023 Common Reporting Standard Updates

To address evolving financial structures and enhance cross-border oversight, the Common Reporting Standard was updated in 2023 ^[1]. This revision amended the existing scope of the standard and enhanced due diligence procedures and reporting requirements across global financial institutions ^[1]. To operationalize these enhanced obligations under the multilateral treaty structure, the Competent Authorities introduced the Addendum to the Multilateral Competent Authority Agreement on Automatic Exchange of Financial Account Information ^[1].

The addendum serves as a formal legal instrument to add specific information items to the scope of exchanges conducted under the CRS MCAA ^[1]. By adopting the addendum, signatory authorities align their mutual exchange processes with the expanded reporting requirements established in the 2023 Common Reporting Standard update ^[1].

Section 1: Additions to Exchanged Information

Section 1 of the addendum establishes the exact data points that must be collected and exchanged regarding reportable accounts held in other jurisdictions ^[1]. These additions are subject to formal notification pursuant to subparagraph 2(a)(i) of Section 2 of the addendum and are exchanged pursuant to subparagraph 2 of Section 2 of the CRS MCAA ^[1].

The first addition requires reporting on whether a valid self-certification has been provided for each Account Holder ^[1]. This provision ensures tax administrations receive explicit confirmation that documentation regarding account holder tax residency has been obtained and validated in accordance with due diligence rules ^[1].

The second addition addresses entity account structures, mandating reporting on the specific role or roles by virtue of which each Reportable Person that is a Controlling Person of an Entity Account Holder qualifies as a Controlling Person of that Entity ^[1]. In addition, reporting institutions must state whether a valid self-certification has been obtained for each such Reportable Person ^[1].

The third addition covers account classifications and structures ^[1]. Tax authorities must exchange details concerning the specific type of account, whether the account is categorized as a Preexisting Account or a New Account, and whether it is held jointly ^[1]. In the case of joint accounts, reporting must also specify the precise number of joint Account Holders ^[1].

The fourth addition applies to Investment Entities structured as legal arrangements ^[1]. Where an Equity Interest is held in such an entity, the exchange must identify the role or roles by virtue of which the Reportable Person is an Equity Interest holder ^[1].

Implementation Mechanics and Signatory Status

The implementation of these expanded reporting rules depends on formal accession by national competent authorities ^[1][7]. The Organization for Economic Co-operation and Development (OECD) coordinates the agreement and publishes official updates detailing the participation status and signing dates of member and partner jurisdictions ^[6][7]. On August 26, 2026, the OECD published an updated list of signatories to the addendum ^[6][7].

According to the official status document current as of August 26, 2026, a total of 81 jurisdictions have formally signed the Addendum to the CRS MCAA ^[6]. These signatories include major global financial hubs, developing economies, and overseas territories across Europe, the Americas, Asia, Africa, and Oceania ^[6]. Among the early signatories adopting the agreement in late 2024 were Austria, Barbados, Belgium, Brazil, Bulgaria, Canada, the Cayman Islands, Costa Rica, Cyprus, Czechia, Denmark, Estonia, the Faroe Islands, Finland, France, Germany, Gibraltar, Greece, Guernsey, Indonesia, Ireland, the Isle of Man, Israel, Italy, Japan, Jersey, Korea, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Malta, Monaco, the Netherlands, New Zealand, Norway, Poland, Portugal, San Marino, Singapore, the Slovak Republic, Slovenia, South Africa, Spain, Sweden, Switzerland, Trinidad and Tobago, and the United Kingdom ^[6].

Throughout 2025 and 2026, additional jurisdictions completed their domestic processes and signed the addendum ^[6]. These include Albania, Anguilla, Antigua and Barbuda, Argentina, Armenia, Bahamas, Bahrain, the British Virgin Islands, Chile, Colombia, Croatia, Ecuador, Hungary, Iceland, Kuwait, Macao (China), Mauritius, Mexico, Moldova, Mongolia, Montenegro, Montserrat, Oman, Panama, Papua New Guinea, Peru, Romania, Rwanda, Saudi Arabia, the United Arab Emirates, and Uruguay ^[6].

Structural Impact on International Compliance

The integration of the 2023 Common Reporting Standard updates into the CRS MCAA reinforces multilateral tax governance by providing tax administrations with granular account data ^[1]. By standardizing information on self-certifications, controlling person capacities, joint ownership metrics, and equity roles in legal arrangements, the framework provides participating jurisdictions with consistent and actionable records ^[1]. Coordinated tracking by the OECD and ongoing domestic enactments ensure that cross-border transparency standards continue to evolve in tandem with global financial markets ^[1][6][7].

Sources

1. Text of the Addendum to the CRS Multilateral Competent Authority Agreement www.oecd.org
2. Signatories of the Addendum to the CRS Multilateral Competent Authority Agreement www.oecd.org
3. OECD Posts Updated List of Signatories to MCAA-CRS Addendum news.bloombergtax.com