According to an update from the OECD, San Marino deposited on 11 December 2025 its instrument of ratification for the Multilateral Convention to Facilitate the Implementation of the Pillar Two Subject to Tax Rule (STTR MLI). San Marino signed the STTR MLI on 19 September 2024, which provides for the implementation of the STTR in bilateral tax treaties. The STTR allows jurisdictions to "tax back" where defined categories of income are subject to nominal tax rates below the STTR minimum rate …