The article examines the legislation on banking activities in the EAEU member countries in order to identify the specifics and analogies of the provisions regulating the activities of systemically important credit institutions. The author concludes that there are no significant differences in the methods used to determine systemically important banks, as the national methods are based on the same recommendations developed by the Basel Committee on Banking Supervision. This allows for the creation of unified requirements for systemically important banks within the EAEU, which will contribute to the further harmonious development of the common financial market of the economic union.