ISO/TS 12812-4:2017 provides comprehensive requirements and recommendations, as well as specific use cases for implementation of interoperable mobile payments-to-persons. The emphasis is placed on the principles governing the operational functioning of mobile payments-to-persons systems and processes, as well as the presentation of the underlying technical, organizational, business, legal and policy issues, leveraging legacy infrastructures of existing payment instruments (see ISO 12812‑1:2017, Annex C). ISO/TS 12812-4:2017 includes the following items: a) requirements applicable to mobile payments-to-persons; b) recommendations regarding mechanisms involved in the operation of interoperable mobile payments-to-persons; c) a description of the different use cases for mobile payments-to-persons; d) a generic interoperability model for the provision of different mobile payments-to-persons; e) recommendations for the technical implementation of the generic architectures for the mobile payments-to-persons program; f) recommendations for mobile remittances; g) use cases with the corresponding transaction flows; h) discussion of the financial inclusion of unbanked and underbanked persons (Annex A); i) some legal aspects to consider for mobile payments-to-persons (Annex B). ISO/TS 12812-4:2017 is structured as follows: - Clause 6 sets forth the requirements that a mobile payments-to-persons program must comply with. - Clauses 7, 8 and 9 provide the different levels of implementation for the interoperability of mobile payments-to-persons. - Clause 7 describes the interoperability principles for mobiles payments-to-persons. - Clause 8 describes: a three-layer high-level architecture for mobile payments-to-persons programs; payments instruments sustained by these programs; processing details for a series of significant use cases of mobile payments-to-persons using these payment instruments. - Clause 9 provides a step-by-step data flow description for different mobile payments-to-persons implementations: bank-centric, non-bank centric and card-centric. They can be mapped into the processing use cases of Clause 8, where abstraction is made in the nature of the payment service providers.