this regard, the EU Internal Market as the most developed and sophisticated economic integration project (Howarth and Sadeh, 2010) represented a 'cornerstone of European integration' (Egan and Guimarăes, 2012, p. 1) and created necessary foundations for EU Member States´ integration also in other areas. The EU nowadays represents more than an economic cooperation or cooperation taking only economic benefits into account. Up until 2016, the EU integration process was accompanied by a parallel enlargement and deepening of integration (Kelemen, Menon and Slapin, 2014) and for the first time in history the EU today is facing a process which is reverse in relation to what we have known so far. The disintegration of the EU (Patomäki, 2017), leaving the EU (Bachmann and Sidaway, 2016), exit from the EU (Welfens, 2016), withdrawal from the EU (Pain and Young 2004) can be used as significant naming of this process. From the point of the EU Internal Market, the events preceding and following the voting of Great Britain leaving the EU once more raised the need to deal with questions about EU integrity and functioning of its internal market. In this article the attention won't be focused on Brexit consequences regarding the EU Internal Market. However the EU Internal Market problematic is as pertinent today as in the past it was. Rueda-Cantuche et al. (2013) highlighted the importance of the EU Internal Market and of the European integration in the context of employment creation in the EU, by pointing out a faster economic growth of open economies. According to Egan and Guimarăes (2012) the EU Internal Market has to be considered not only as a fulfilment of the EU primary law obligations, but also as a key factor for entrepreneurship, growth and employment by supporting the competitiveness. Functioning EU Internal Market is particularly important for those businesses, trading across borders (Guimarães and Egan, 2014). A common space between the EU Member States (Kostadinova, 2013), in the form of the EU Internal Market significantly helps to attain economic growth within the EU (Badinger, 2005) and to create jobs and to increase employment (Rueda-Cantuche et al., 2013). Despite its importance, there are still deficiencies of the EU Internal Market. Pelkmans and Mustilli (2014) confirmed existing EU Internal Market´s deficiencies and in this regard they stated that a minimization of these deficiencies would result in additional GDP growth in the EU and in the individual EU Member States´ economies. Siim Kallas as a European Commission Commissionaire for Transport and a Vice-president of the European Commission in 2010-14 in this regard noted, that one of the best ways to boost economic growth is the removal of barriers in the EU Internal Market (European Commission, 2015i).