This study reveals the comparative analysis of the tax system of Denmark, Norway and the Republic of Moldova. Despite the fact that Norway and Denmark have a progressive taxation system, they have demonstrated a high level of social and economic well-being, which is due to the awareness of all economic agents, including households, that taxes and fees contribute to ensuring sustainable development. Sustainable development reveals all the methods and forms of socio-economic development, which focus on ensuring the balance between ecological, economic, and social aspects and the elements of natural capital. At the same time, in order to ensure a high level of quality of life and sustainable development, ways of connecting the tax system of the Republic of Moldova to international practices are being researched.