This note analyses the rules governing the calculation of the effective tax rate for the purposes of the GloBE Rules and Pillar Two. The author examines possible discrepancies with other Member States’ legislation, including Italy’s, and suggests possible amendments. It starts with an analysis of the Italian regime, devoting particular attention to a comparison with the Globe Rules regarding the treatment of income derived from dividends and capital gains. The aim of this comparison is to provide an example of the possible difficulties that national legislators will face in promoting the forthcoming reforms.