Unified Payments Interface, commonly referred to as
UPI, is an Indian instant payment system as well as protocol developed by the National Payments Corporation of India (NPCI) in 2016. The interface facilitates inter-bank peer-to-peer (P2P) and person-to-merchant (P2M) transactions. It is used on mobile devices to instantly transfer funds between two bank accounts. The mobile number of the device is required to be registered with the bank. The UPI ID of the recipient can be used to transfer money. It runs as an open source application programming interface (API) on top of the Immediate Payment Service (IMPS), and is regulated by the Reserve Bank of India (RBI). Indian Banks started making their UPI-enabled apps available on Google Play on 25 August 2016.