How does the UPI payment gateway work?

UPI, or Unified Payments Interface, is a real-time instant inter-bank payment system developed by the National Payments Corporation of India (NPCI). It works via an API-based architecture, allowing users to link multiple bank accounts to a single UPI app. When a transaction is initiated, the app facilitates the instant transfer of funds directly between bank accounts, leveraging a unique UPI ID for secure and seamless payments.