UPI begins as an interoperable payments pilot
The National Payments Corporation of India launched the Unified Payments Interface pilot on 11 April 2016 with 21 member banks. UPI provided a common interface for immediate bank-to-bank push and pull payments; participating banks began releasing enabled apps in August.
The pilot launch is distinct from the later public availability of bank apps and UPI’s subsequent expansion. This dated card does not project later transaction volumes back onto 2016.
Source: NPCI: UPI launch press release