As far as the norms of the Code of Administrative Procedure (CAP) are concerned, there is no other category of entities other than a party to the proceedings who could request the authority’s action or whom the authority’s action might concern, as was the case in the regulation of the President of the Republic of Poland of 1928, preceding the CAP, regulating the institution of the person concerned. In the CAP regulation, in the scope of the category of parties to the proceedings, the legislator distinguished parties with disputed interests. The disputed interest is most often manifested in the fact that one of the parties requests the initiation of proceedings in order to obtain a specific entitlement, and the authority deciding in this regard must do so in such a way as not to infringe on the legal interest of other persons (third parties) who, due to the interest in question, in order to ensure its proper protection, use and enjoy the status of a party in the proceedings. For delimiting the above categories of the parties to proceedings, the doctrine and the case-law assume their division into parties with the so-called main rights and parties with the so-called reflexive rights. In the context of the underlined distinction of both sub-categories of parties to proceedings, the object of the analysis of this study is the question of whether or not, according to the provisions of the CAP, the differentiation of their procedural rights can be made. To this end, it was justified to refer to the institution of repealing or amending a final decision pursuant to Article 155 of the PAC, in view of the positions that are presented in the caselaw of the administrative courts in the context of this provision.