US Pushes Three Changes to Global Minimum Tax Rules

The United States is proposing three major changes to the Global Minimum Tax (GloBE) rules. The proposal was presented by Assistant Deputy for International Taxation Rebecca Burch in Washington, D.C., on 9 December 2025.

The first change would exempt multinational groups with a U.S. ultimate parent from the Income Inclusion Rule (IIR) and Undertaxed Payment Rule (UTPR). The second introduces a permanent safe harbour, prepared by the OECD, to simplify effective tax‑rate calculations for non‑U.S.

If adopted, the reforms could lower compliance costs for U.S. multinationals and align the side‑by‑side system agreed by the G‑7. Implementation is expected to be finalized by the end of the year through the Inclusive Framework.