Saritha Rai, reporting for Bloomberg: India is trying to yank its cash-based economy into the 21st century. But how do you get 1.2 billion people, many of whom have never seen a bank or opened an account, to send digital payments to each other? The government's answer is an effort it has named the Unified Payment Interface. Debuting Monday, it's a system designed to make transferring and receiving money as easy as exchanging e-mail or text messages. The goal is to bring banking and financial services to hundreds of millions of citizens, many of them poor and disadvantaged, in one fell swoop. The network was created by India's retail banks and backed by India's central bank -- and they're confident it will work because it's built on top of an even more audacious project: India's biometrics-enabled national ID system, called Aadhaar after the Hindi word for foundation.The idea is to make mobile payments and utilization of other services between users with accounts in different banks frictionless. The Aadhaar number, or a virtual address, will serve as the single identifier. This will also allow a person to use several services of a bank without being its customer, explains Forbes India. The UPI app is in phase-I and is operational for a closed user group. The app is expected to be launched for public in the coming months.