Action 15 of the BEPS Action Plan provides for an analysis of the tax and public international law issues related to the development of a multilateral instrument to enable countries that wish to do so to implement measures developed in the course of the work on BEPS and amend bilateral tax treaties. On the basis of this analysis, interested countries will develop a multilateral instrument designed to provide an innovative approach to international tax matters, reflecting the rapidly evolving nature of the global economy and the need to adapt quickly to this evolution. The goal of Action 15 is to streamline the implementation of the tax treaty-related BEPS measures. This is an innovative approach with no exact precedent in the tax world, but precedents for modifying bilateral treaties with a multilateral instrument exist in various other areas of public international law. Drawing on the expertise of public international law and tax experts, the 2014 report, explored the technical feasibility of a multilateral hard law approach and its consequences on the current tax treaty system. It identified the issues arising from the development of such an instrument and provided an analysis of the international tax, public international law, and political issues that arise from such an approach. The 2014 report also concluded that a multilateral instrument is desirable and feasible, and that negotiations for such an instrument should be convened quickly. Based on this analysis, a mandate for the formation of an ad hoc Group to develop a multilateral instrument on tax treaty measures to tackle BEPS, which is reproduced hereafter, was approved by the OECD Committee on Fiscal Affairs and endorsed by the G20 Finance Ministers and Central Bank Governors in February 2015. The Group is open to participation from all interested countries on an equal footing and is served by the OECD Secretariat. The Group begun its work in May 2015 with the aim to conclude its work and open the multila