The legal system in force in Poland protects personal data of all Polish citizens. This system was developed along with political changes in the 90s of the last century. For several decades of its application, it was amended to create tools for a more effective and efficient system that protects the well-being of all inhabitants. Creating a system of law is the task of the Lower House and the Senate, but as a member of the European Union, Poland is also obliged to apply EU law. In this respect, legislative activity is relatively dynamic, since for many years the aim has been to introduce uniform security standards throughout the whole European Union. These standards come into force as early as of May 2018 and actually change many regulations in the existing protection rules. The aim of the paper is to present the current principles of protection and discuss the most important regulations introduced by the EU law and the effects of their application on Polish entrepreneurs.