The supplementary tax (also known as QDMTT or Pillar Two) is Switzerland’s implementation of the international OECD minimum taxation of 15%. It applies to large, internationally active corporate groups with consolidated annual revenue of at least 750 million euros.

Since 2024, the supplementary tax has been in force in Switzerland (partially extended from 2025). The aim is for large corporations worldwide to pay at least 15% tax on their profits. If the effective tax burden is lower, a supplementary tax must be paid subsequently in Switzerland.

Who is this relevant for? Only for Swiss companies that are part of a large international corporate group. Pure Swiss SMEs or smaller companies are generally not affected.

In recent months, the ESTV has published several detailed communications on practical application (e.g., on election rights, permanent establishments, and distributions).