As a consequence of Hungary's accession to the EU the Hungarian Competition Authority is obliged to apply the Community rules to conducts (restrictive agreements and abuses of dominance) to which it may apply national competition law and which fall under Community competition rules due to their effects on trade between Member States. In the competition law of the EC, restrictive agreements are regulated by Article 81 of the Treaty establishing the European Community (EC Treaty) while the rules concerning abuse of dominance are laid down by Article 82. The GVH has the possibility to apply national law even parallel to the Community competition law.

According to the rules of the Community not only the Commission but also the competition authorities of the Member States are entitled - and required at the same time - to enforce the Community competition rules. When applying the Community competition rules the national competition authorities (NCAs) apply their own national procedural rules.

According to the rules of the Community's procedural regulation (Regulation (EC) No 1/2003 on the implementation of the rules on competition laid down in Articles 81 and 82 of the Treaty) and the Commission Notice on cooperation within the Network of Competition Authorities, the Commission and the NCAs closely co-operate in the course of application of Community competition law. In the framework of this co-operation, it is possible to allocate cases and exchange information between competition authorities.

The information exchanged in the proceedings initiated by the Member States- authorities may be used to prove infringements of the competition rules as well. In the course of co-operation the competition authorities can help each other-s proceedings with the performance of procedural acts.