A multilateral instrument that will protect the right of developing countries to ensure multinational corporates pay a minimum level of tax has been adopted by countries supporting the Organisation for Economic Co-operation and Development’s (OECD) global tax reform efforts. Developed over the past 12 months through negotiations between governments supporting the OECD, including OECD members and G20 countries, the Multilateral Convention to Facilitate the Implementation of the Pillar Two Subject to Tax Rule is a major step in concluding Pillar Two of the OECD’s proposed reforms, which would introduce a 15% tax minimum for multinationals. The multilateral instrument will allow countries to implement the Subject to Tax Rule (STTR) in existing bilateral tax treaties. OECD Secretary-General Mathias Cormann said: “Adoption of this new multilateral instrument […] reflects how productively and positively the international community is working together to deliver solutions for developing countries. Importantly, the STTR sets out a comprehensive provision to ensure that developing countries are able to ‘tax back’ in instances where payments sourced in their jurisdiction are not taxed at a minimum rate in a partner jurisdiction. The opening of the multilateral instrument for signature marks further progress towards the implementation of the Pillar Two minimum tax, as well as a major further step to stabilise our international tax system and to make it fairer and work better.” The OECD will serve as the depositary of the instrument, supporting governments, while further preparing an action plan to support the co-ordinated implementation of Pillar Two.