The consent of a party, which determines the admissibility of the administrative authority to take certain procedural actions, is one of the three most important instruments of his or her protection in administrative proceedings, next to the right to actively participate in the proceedings and the right to appeal against the decisions made. Actions requiring the consent of a party include: conducting the proceedings initiated ex officio in a matter requiring an application of a party, mediation, examining a party, stay or discontinuance of the proceedings despite the lack of objective reasons for it, the so-called self-control of the first instance authority, supplementation of evidence by the appellate authority and quashing or changing the final decision despite its compliance with the law. The paper analyzes, on the one hand, the considerations justifying the authority’s taking the above actions; on the other hand, the reasons why the provisions of law provide the party with the opportunity to block such actions of the authority by not expressing consent, i.e. potential or actual adverse consequences for the party resulting from such actions.