From the far beginning of the European Communities, with broader objective of creating a perfect unique market for the member states, it must be underlined the importance of the results of the harmonisation process of the contract law and the single market and that, in time, the institutions struggled in their tumultuous work for fulfilling the indicated objectives to overcome the interventions from each Member State, interested, also, in shaping a great and prosperous common market, but trying, subsequently, to reason with their traditions, culture, ideological and political choices. The legislation on single market and European contract law is a subjected to the three guiding principles of the European Union: the principle of conferral, which empowers the European Union in terms of competence, the principle of subsidiarity, which underlines the European Union's competence in a certain field that is shared with a Member State and the principle of proportionality, which applies if the first two principles are validated, dealing with the how the European Union should legislate. However, there are some critics who express their worries in that there are insufficient empirical proofs for redefining the harmonisation process. Taking into account the criticism, the European Court of Justice has ruled in numerous occasions that the authorisation to harmonise laws, with the scope of safeguarding the proper functioning of the European internal market does not grant the European Union a carte blanche in order to interfere with the sake of harmonisation any law it wishes. The way the above indicated principles maintained their roles provided by the treaties or they were subject of modification, by enrichment or limitation, by the caselaw provided by the European Court of Justice, we must investigate in order to picture a possible “finale” of our Single Market and this paper will concentrate of the influence of subsidiarity and proportionality on the fields most dynamic in the past years, the Digital Single Market and its contract law. This paper wishes to clarify how the two fundamental principles, of subsidiarity and proportionality, provided in time by the modifying treaties and consolidated by the European Court of Justice, influenced the evolution of the legislation regarding the Single Market and how those two may help or block the future evolution in the context of a continuous pressure coming from the development of the digital framework and online contracts
