Illegal practices that infringe competition law may - besides violating the public interest, which is safeguarded by the GVH - cause individual harm (mainly damage) to consumers, market players or other persons affected. Consequently, actions against violators of the competition law may take two forms. The GVH may commence an investigation where it is necessary to safeguard the public interest, in order to terminate and (if necessary) sanction the violation. On the other hand, the persons whose rights were infringed can file civil law claims and thus directly enforce the provisions laid down in the Competition Act. The court may grant damages or may even form contractual relationships (e. g. it may establish contracts between the parties, compel them to perform contracts or, after establishing that the contract is illegal for it restricts competition, it may apply the consequences of invalidity).

In civil lawsuits, the GVH as amicus curiae may submit its (written or oral) observations on issues relating to the application of the unfair-manipulation-of-consumer-choice, restrictive-agreements and abuse-of-dominance provisions of the Competition Act and of Articles 81 and 82 of the EC Treaty.