ABSTRACT
It is devoted to analysing the extent to which the principle of legal certainty affords individuals protection in the course of national fining proceedings. The chapter analyses this principle as an umbrella principle that covers several specific rights of individuals and the duties of national authorities arising from the principles of non-retroactivity of fining legislation (lex retro non agit) and the duty to apply less stringent fining laws (lex mitior). It discusses the impact of this principle on the interpretation and application of both substantive and procedural rules applicable to fining proceedings. It considers whether the principle of legal certainty limits the effectiveness of EU substantive law in protecting EU fundamental rights or general principles.
