This study is devoted to a comparative analysis of different models of the risk-based approach used in tax administration in the BRICS countries. The risk-based approach is widely recognized as the fundamental basis for defining and legally consolidating the tasks of tax administration bodies in modern conditions. According to this approach, the objectives of the tax administration are to identify, prevent and minimize threats to tax security in the course of the implementation of the full range of administrative functions in the tax sphere, as well as to work towards overcoming the consequences of the realization of threats. The authors propose the following points for conducting a comparison of the BRICS countries using tax risk assessment: the implementation of risk assessment in the practice of tax administration and the quality of its legislative regulation, the impact of risk indicators on the behavior of taxpayers and the impact of risk indicators on the effective implementation of tax control measures. In general, there is a high degree of similarity among all aspects of the risk-based approaches adopted in the BRICS countries. However, the methods of implementation and levels of legal certainty in laws differ from country to country.