The laws of the Member States of the European Union and the tax treaties concluded by them - being part of their national laws - must be consistent with European Community law. Apart from EC Directives and Regulations, the EC Treaty itself contains rules directly applicable to matters of international taxation. In this context the decisions of the European Court of Justice on the fundamental freedoms laid down in the EC treaty are of primary importance. If a provision of a tax treaty is in conflict with the EC Treaty, it is superseded by the Treaty provisions. The EC Treaty may therefore have the effect of changing the content of tax treaties, a matter of crucial importance to international tax planning techniques.