The interplay between European and national law poses considerable problems not only from a legal perspective. Enterprises also face economic challenges as the absence of a European “level playing field” leads to rising transaction costs. This article uses the example of the PRIIP Regulation to illustrate the interplay between the various hierarchical levels of European law and attempts to provide a methodological solution for yet unresolved issues. Finally, the article raises the question whether the PRIIP Regulation has really achieved its legislative objectives.