The article defines the theoretical basis for the interoperability of payment systems, presents its structural classification. As part of the structural classification, levels, types, forms of interoperability for payment systems are specified. Interoperability of distributed ledgers is reviewed. One of the main tasks of the development of the payment services market is the integration of conceptual, technical, organizational, regulatory solutions into a unified project that allows for the successful implementation and development of interoperability. Recommendations are made to the regulator on the implementation of interoperability in the payment services market, the participants of which are both credit organizations and fintech companies, which will allow them to increase efficiency and reduce costs.