The actual article is devoted to the study of the one of the possible ways to construct the unified payments area on the basis of existing national operating infrastructures. It is proposed, that the fundamental units for such area could be national payments systems of the member states of the Eurasian Economic Union due to the fact, that, as of today, despite the promising EAUE's geopolitical market position, it doesn't have any cross-border payment system or, at least, a mechanism for transferring of funds within the interconnections between legal entities within the EAEU's market, which affects negatively on the development of trade and economic relations. Article contains the following main conclusions and authors' elaborations: • proposes the general architecture of the unified payment area in the form of the payment system (RIFTS), states the general criteria for participation and identifies the problem of building the state's supervision structure on the international level; • describes the proposed RIFTS transactional capacities and channels; • presents the concept of the 'two-tier liquidity' and deduced formulas for calculating the minimum and optimal amount of funds within the concept.