The taxes that a state charges are established by the respective internal laws, they constitute a sovereign right of the state. According to art. 4 and 8 of the Constitution of the Republic of Moldova, individuals have fundamental duties, established by treaties and international conventions ratified by the Parliament of the Republic of Moldova, which are an integral part of domestic law. In this context, the entry into force of an international convention or treaty containing provisions contrary to domestic law, will directly implement the international act ratified by the state - the Republic of Moldova. The subjection of a taxable matter, by two different states, to the same type of tax, within the same financial year, is known as double international legal taxation. This phenomenon is produced not due to the different structures of the tax systems or the different degree of taxation in the considered states, but rather to the conceptual diversities, which are the basis of taxation, a fact which determined that through international conventional norms to mitigate these double taxation processes.