56However, as soon as a Member State, either unilaterally or by way of a convention, imposes a charge to tax on the income not only of resident companies but also of non-resident companies from dividends which they receive from a resident company, the situation of those non-resident companies becomes comparable to that of resident companies (see, to that effect, Test Claimants in Class IV of the ACT Group Litigation, paragraph 68; Denkavit Internationaal and Denkavit France, paragraph 35; Amurta, paragraph 38; Commission v Italy, paragraph 52; and Commission v Spain, paragraph 51).