The GVH enforces the provisions of the Competition Act and the EC competition law in competition supervision proceedings. The Competition Act and, as a background legislation, Act CXL of 2004 on the General Rules of Administrative Procedures and Services (Public Administrative Procedures Act, PAPA) contain the provisions on the initiation, performance and conclusion of the competition supervision proceeding. The PAPA applies to the procedure of the GVH only insofar as the Competition Act, which contains specific procedural provisions for the GVH, does not establish rules different from those of the PAPA.

The competition supervision proceedings of the GVH are initiated ex officio or commenced on application.

In the proceedings based on the substantive law provisions of the Act on Trade, the GVH applies the procedural rules and certain other provisions of the Competition Act that govern its procedure in abuse of dominant position cases. When approving commercial code of ethics, the GVH acts solely according to the provisions of the PAPA, since neither the Act on Trade nor the Competition Act contain special rules for procedures which are commenced on application and conducted under the substantive provisions of the Act on Trade.