The beneficiary, by signing the project contract, undertakes to ensure correct implementation of the project by preventing fraud. Therefore, it is necessary to verify the implementation of the project in terms of the occurrence of possible abuses or irregularities. The article presents the instruments and principles of verification of the correctness of spending of funds allocated for the implementation of cohesion policy, in particular in the context of the requirements arising not only from normative acts, but also from soft law. The research carried out was aimed at analysing the principles of approximating the issue of detection and correction of irregularities in relation to the Guidelines in force in the current perspective – which has not yet been the subject of in-depth analysis and in this respect this article fills the research gap. The subject of the study also included the issue of calculating the amount of financial correction, due to the numerous doubts about the issue in question arising in practice. The author, using the dogmatic-legal and legal-comparative methods, sought answers to the question of how to protect the implementation of projects from possible irregularities, as well as how to recover improperly spent funds. The above issues are of particular importance in the context of imposing financial corrections, as the rules for imposing corrections have undergone certain modifications, which was presented by comparing the current financial perspective to the previous one (2014–2020).

The most numerous group of beneficiaries applying for grants from EU funds are entities of the public finance sector obliged  to  obey  the  regulationsof  the  PPL.  The  implementation  of  EU  funds  is  connected  with  a  number  of  legal regulations, both at the EU and Member State level, and the effective absorption of EU funds is inextricably linked to public  procurement  law  procedures.  This  article  presents  the  absorption  of  EU  funds  from  the  largest  operational program in the context of public procurement law procedures, as well as issues related to irregularities identified in the co-financed procurement process.