Recently the ECJ has stated that EU law precludes national legislation like section 10 paragraph 2 of the Austrian Corporate Income Tax Act, which subjects portfolio dividends received from companies seated in non-member states to economic double taxation, whereas nationally sourced dividends are completely exempted from such an effect. Nevertheless, in light of the equivalence between the exemption and the credit method, it is for the member state to determine the preferred method; difficulties that a taxpayer might encounter in order to prove that the conditions for a relief from double economic taxation are met do not preclude a switch-over or even the credit method itself. However, it is compatible with EU law to grant a relief in connection with portfolio dividends from non-member states only if an agreement for mutual assistance in administrative matters exists with that state. Furthermore, the ECJ has concluded that it is necessary to grant a credit carry-forward for foreign corporate income tax in a loss situation.