Tax policy, perceived as a long-term and rational activity which aims to achieve specified legal, economic and social goals has always been connected with the problem of political power within the frames of a given tax system. Regarding the nature of membership in the European Union, issues of tax policy should be analyzed in the context of a ulticentric tax system, since both creators and addressees of political actions remain in a diverse regime of domestic, European and international tax law. The author discusses the legal basis of this phenomenon, which attributes to the complementary nature of the tax policy, reflecting on the conditions and limitations
in the light of challenges to be faced by contemporary tax systems.