Unified Payment Interface — a payment application by which a recipient can initiate the payment request from a smart-phone — has been made operational following final approval from the RBI, the National Payments Corporation of India said. Banks will install the UPI app on the Google Play Store over the next two-three days. “Real-time sending and receiving money through a mobile application at such a scale on interoperable basis had not been attempted anywhere else in the world,” said A. P. Hota, MD & CEO, NPCI. Most leading banks such as ICICI Bank, Axis Bank, Punjab National Bank, Union Bank of India have tied up with NPCI for the service. The UPI app of 19 banks will be available on the Google Play Store in the next two to three working days for the customers to download and begin start using the app, it added.