Comments on the Side-by-Side Package to the Global Anti-Base Erosion Model Rules

These comments by the BEPS Monitoring Group (BMG) analyse the Package released by the OECD Secretariat on 5th January 2026 agreed by the G20/OECD Inclusive Framework on BEPS. This package provides a further set of ‘administrative guidance’ for the implementation of the Model Rules of the global anti-base erosion (GloBE) tax that aims to ensure a global minimum tax on multinational enterprises (MNEs). Its main component is a ‘Side-by-Side System’, designed to provide compatibility with the GloBE for the US tax rules on MNEs. Despite this focus on the US, it has been formulated as standards with which the rules of any country, including the US, must comply to ensure such compatibility.

We aim here to provide an analysis and critique of the global minimum tax as well as the effects of this package. Very regrettably, there has been no public consultation on these changes. Indeed, the entire process of formulation of the GloBE has been conducted largely out of sight, through a combination of secret political negotiations and a fog of technical complexity. The OECD has responded to complaints from business lobbyists and tax advisers by consulting and even closely collaborating with them in some aspects, to ensure their cooperation with technical compliance, but behind closed doors. Yet taxation, especially of giant MNEs, is of central political importance, and amongst the highest concerns of the public around the world. It should not be acceptable that these crucial questions are dealt with largely in secrecy and beyond the reach of any public debate or accountability.