Why did the EU need a single VAT system

VAT in the European UnionOne of the principles of the EU was declared "freedom of movement of goods." This implied the abolition of customs borders within the EU and the abolition of customs duties. But on the other hand, this did not mean the abolition of other "input" taxes (including VAT), which greatly complicated the movement of goods between EU countries. It was to simplify these procedures that it was decided to introduce a unified system of VAT taxation within the EU. When describing the European VAT system, it is necessary to take into account the specifics of the European Union. Formally, the EU members are independent states, however, at the same time, they transferred part of their sovereignty to the highest governing bodies of the EU for a common European policy in one area or another. In order to establish a single legislative regulation, EU bodies adopt binding decisions (directives) for implementation, after which all member states are obliged to bring their domestic legislation into line with the requirements of the adopted directives. Most often, EU directives establish only general principles and goals in a particular area, leaving national legislators some freedom of action when implementing the provisions of the directives in their legislation. This also affected the regulation of the European VAT system. Despite the fact that the general principle of collecting this tax is the same for everyone, each EU country has its own specific features of its regulation. This approach over time has led to the fact that the system of charging VAT in the European Union has become quite complex and confusing. More here - https://europa.eu/european-union/topics/taxation_en