The cross-border taxation of partnerships is characterized by the transparency principle, i.e. by the international application of the co-entrepreneur principle (co-entrepreneur). With taxation based on the principle of transparency, it is not the company itself that is charged, but its shareholders.
Problems arise in international tax law, however, because partnerships are treated differently in different countries. Such qualification conflicts make it difficult to harmonize direct taxes. Only for the European Economic Interest Grouping (EEIG) is the principle of transparency mandatory for all member states. This enables the approach of a relatively uniform taxation of this legal form.