Abstract
This article analyses the limits to Member States’ powers in the field of enforcing (criminal) penalties for infringements of EU law, with particular focus on the protection of the EU’s financial interests. The article addresses the issue of the broad interpretation of the concept of ‘fraud’ within the meaning of Article 1(1) of the PFI Convention, which resulted in imposing an obligation on Member States to establish criminal penalties for certain serious VAT fraud. Next, the article analyses the requirements of effectiveness and equivalence of penalties established in domestic law for infringements of EU law, which may affect not only the severity of penalties, but also the rules of criminal procedure (limitation periods in pre-trial and judicial proceedings). Finally, the article presents the main developments in the context of limitations of ius puniendi, which stem from the obligation to protect fundamental rights under the Charter of Fundamental Rights.