Achieving financial sustainability is the most important strategic task of the state in a turbulent global economic environment. The purpose of this study was to identify the patterns of development and peculiarities of the tax situation in Russia. The authors determined the most effective approaches for the formation of the tax system that would ensure the financial sustainability of the state in conditions of economic transition. This study examined the existing features and patterns of the formation of the Russian tax system. The ways and instruments to achieve financial stability were considered. As an example, it was decided to take into account the international practices of the most successful states in terms of tax (according to the Doing Business methodology)—namely, the USA, Ireland, France, Greece, Luxembourg, the Netherlands, Germany, Switzerland, the UK, Sweden and Norway. A list of conditions is proposed, the implementation of which might ensure the transformation of the Russian financial system in terms of sustainability. This article also demonstrates changes in the economic infrastructure of the Russian Federation and indicates possible scenarios for the development of the tax system. This study determines that the tax system is largely shaped by the information environment. Therefore, digitalization processes can serve as a catalyst for the achievement of financial sustainability by the state. The choice of tools for the internal reform of public finances is situational. However, strategic transformation (in terms of macro-level sustainability) can be achieved by performing a number of universal steps. The implementation of the latter creates not only a positive effect from the introduction of new approaches, but primarily minimizes the impact of existing negative phenomena and trends. The tax system of the Russian Federation can be optimized by consolidating sustainable development indicators in the legal acts. The latter is an important step towards achieving financial sustainability.