Information that is important for taxation as an element of the legal regime of secrecy in tax relations is considered in the article. A critical assessment of the regimes for the protection of secret and confidential information about taxpayers provided for in the Tax Code of Ukraine is given. Based on the analysis of doctrinal works and domestic legislation the main structural elements of the legal regime of tax secrecy are identified, their content is researched. The main problems of legal support of the institute “information relevant to taxation” are highlighted. It is stated that most structural elements of this regime are not defined by the law and are scattered at the level of a number of regulations of different legal force. The necessity of elaboration and adoption of a normative-legal act, where the conceptual bases of the legal regime of tax secrecy in Ukraine would be determined, is offered. Recommendations on the transition from the prohibitive principle of tax secrecy in terms of openness and public access of information, which operates in Ukraine, to the permissive principle are substantiated. It is proved that the regime of professional secrecy of tax officials of Ukraine is optimal in the context of protection of taxpayers’ rights and development of tax service functions.