This paper presents one of the latest measures taken by the EU to achieve the objectives of the European construction. This paper deals with the consequences of signing the Treaty on the establishment, coordination and governance in the European Union, also known as the "Tax Treaty". Thus, our article presents some general concepts on the relationship between taxation, fiscal policy and the European Union, sketching in the same time the background for the signing of the “Tax Treaty” and highlighting the consequences of the Treaty on member states, especially on budget deficit.