Taxation of business profits is not yet harmonized in the European Union. In its first part this article takes the position that the ongoing tax competition and the growing economic integration calls for a common system of the taxation of EU multinationals. At present the European Commission pursues a concept of a fully uniform Common Consolidated Corporate Tax Base (CCCTB). In view of the slender chances that a directive without any leeway for national alterations will receive the necessary unanimous support of all 27 Member States the second part of this article discusses a less ambitious approach of guided variety by an analysis of the US States corporate income tax system which despite many common features is far from being uniform. In the third part economic and legal consequences of a less uniform CCCTB will be scrutinized.