EN
During the development of the Treaty of Rome it was decided that, to assure a common market, it was enough to harmonise indirect taxes and remove trade barriers as they were the prime inhibitors to the flow of goods and services. The harmonisation of direct (income) taxes was not considered as they were seen as not signifi cantly affecting the single internal market. Problems tied to direct taxation became visible as integration proceeded, the EU grew, its citizens began to migrate, multinational enterprises increased in size and scope and their financial flows (capital and profi t transfers between headquarters and subsidiaries in different EU countries) became seriously affected.