Subject. This article explores the issues related to institutional and financial relations within the integration of financial markets in the EAEU countries on the basis of a single payment area. Objectives. The article aims to develop proposals to arrange a single payment area in the regional integration association of the EAEU. Methods. For the study, I used the general scientific knowledge techniques and examined financial and foreign trade statistics and reviews of the Eurasian Economic Commission, and statistical databases of the World Bank and International Monetary Fund. Results. The article presents proposals to include a new mechanism for building a single payment area in the system of cooperation within the framework of harmonization of financial markets in the EAEU, which is to unite the processes of target setting and building a common format of activities in the field of financial regulation and a single payment infrastructure arrangement. Conclusions. The proposed organizational mechanism for the integration of financial markets in the EAEU can help prepare the financial systems of the EAEU countries for integration and implement it in the most effective way.