The paper considers usage of mobile cloud computing in most regulated procedures of tax administration - taxpayer registration and numbering. The literature review of the research devoted to issues of digital taxation, tax control, tax procedures, general or specific for some states, shows a lack of scientific studies in the inter-country analysis devoted the above-mentioned issues. Therefore, relying on the experience of difference states, the authors set goals of the current research, which are to identify positive and negative aspects of integrating information and communication technologies in registering and accounting tax procedures; to come up with guidelines for tax procedure improvements. The research was conducted by two groups of countries with different geographical locations: economically developed countries (USA, United Kingdom, Switzerland, Sweden) and developing countries (Mexico, Kenya, Indonesia, Mongolia), and the Russian Federation. Based on the data of the "The Global Competitiveness Index 4.0" 2018 rankings (World Economic Forum), the authors evaluated digitalization in the countries under analysis and its impact on tax relations. The World Bank "Paying Taxes" rankings 2011- 2019 showed development of the particular tax subsystem - tax administration, determined by the intensive use of progressive technologies. The given paper presents brief characteristics of online services, mobile applications, and other software used now in the countries under analysis. The characteristics resulted from current information from websites of tax regulatory agencies in the countries. The comparative analysis as the main research method made the foundation for both general conclusions and guidelines common for all the states, and individual features that concern the Russian system of tax administration. For this purpose, the authors used the guide of the International Monetary Fund. Suggestions for improvement of tax registering and accounting procedures in Russia cover the current problems in this sphere, including long-term prospects.