The article substantiates the need and importance of digital transformation of tax administration in response to the challenges of deepening digitalization processes in all sectors of the economy and responding to epidemiological threats. The current trends of digital transformation of tax administration according to the subjective approach with the definition of additional economic and social effects for the development of public administration, business environment and welfare of society are identified and characterized. Based on these transformational trends, the qualitative level of digital maturity of tax administration in the world is generalized, which allowed concluding the active form of the global digital space of tax administration, which integrates digital infrastructure and digitalization of taxation processes, information interaction, information resources and tax data and norms of tax regulation, mechanisms of organization and management, as well as to form the tasks of digital transformation at the level of taxation processes. Given that the digital transformation of tax administration does not fundamentally change its essence and elements but concerns procedural issues, the potential of digital technologies is demonstrated in the example of foreign and Ukrainian practices of implementing Blockchain and smart contracts based on Blockchain, Big Data, Artificial Intelligence Technologies, Machine Learning, cloud technologies, the Internet of Things (IoT) as technological tools for the organization of tax relations and tax administration. Attention is paid to problematic aspects of fair taxation of digital business, its products and services (digital assets, digital services, and artificial intelligence and cloud services). The processes of digital transformation of tax administration in Ukraine are described. It is substantiated that to determine the level of effectiveness and the degree of progress of the digital transformation of tax administration, it is necessary to develop a methodology for assessing digital maturity and a system of indicators for specific contours of measurement. This is accepted as the goal of further research to ensure flexible fiscal policy and rapid response to the effects of crises, including the latest epidemiological challenges, improving tax surveillance and compliance control to ensure fiscal stability and tax security, better, transparent and fairer digital tax environment.