The Unified Payments Interface (UPI) is an Indian instant payment system and protocol, a real-time payment system developed by the National Payments Corporation of India (NPCI). It was officially introduced on April 11, 2016, to address the need for a simple, secure, and interoperable digital payment mechanism, aiming to increase non-cash transactions and combat black money. The system is regulated by the Reserve Bank of India (RBI) and is built as an open-source Application Programming Interface (API) on top of the Immediate Payment Service (IMPS).
The core mechanism involves linking a bank account to a unique identifier called a Virtual Payment Address (VPA) or UPI ID, which eliminates the need to share sensitive bank details for transactions. It operates on a four-pillar push-pull model, facilitating both Person-to-Person (P2P) and Person-to-Merchant (P2M) transfers. The transaction is authorized by a secure UPI PIN set by the user. The NPCI acts as the central switch, routing the payment request between the payer's and payee's banks, which are connected through Payment Service Providers (PSPs) and accessed via Third-Party Application Providers (TPAPs) like Google Pay or PhonePe.
Recent changes have focused on expanding its utility and ensuring sustainability. From March 15, 2022, the requirement for a debit card for UPI registration was removed. Furthermore, the RBI permitted the linking of RuPay credit cards with UPI starting June 8, 2022. A significant amendment is the introduction of a Merchant Discount Rate (MDR) of 0.4% on select P2M transactions above ₹2,000, effective October 15, 2026. However, P2P transfers and merchant payments up to ₹2,000 remain free for the consumer.