Economy digitalization calls for an upgrade of all economic processes. The subject of the research in this paper is the RF taxation system, its challenges and possible trajectories of its development defined from the analysis of the national taxation features in post-Soviet countries in the context of the social, economic, and political transformations, as well as from the integration into the global economic space. The analysis of the CIS national taxation systems is advantageous as the countries share national economic systems, political regimes, management systems, economy structures, population mindsets, and borders. The purpose of the research is to explore the taxable incomes to define the real estate taxes in CIS countries to detect the problems and key advantages in the national taxation systems, and this can identify promising areas in improving the RF real estate taxation. Development and justification of possible areas for the RF taxation system improvement, which satisfy the requirements of all subjects of the RF taxation system and provide the better quality of the taxation management, more precise taxable income, decrease the inequality in distributing the tax burden among the tax payers. Substantial results of the research which underlie its novelty are as follows: 1) taxable income features with regard to the national legislative documents which regulate the CIS property taxation are analyzed to calculate the real estate taxes; 2) three main approaches to find the taxable property income (examination of cadastral or other types of public evaluation, reference to the average annual or residual value of real estate, reference to the real estate area) were found; 3) key drawbacks in the acting RF taxation system are grouped; 4) key areas for upgrading the RF real estate taxation by better quality of information, development and introduction of digital tools for a large scale evaluation of property units, digitalization of cadastral data, having more information in the cadaster are offered. Further research is seen to be connected with a more comprehensive analysis of the rules defining fair cadastral property value to remedy the drawbacks in the present evaluation methodology.