If you just want to use the UPI app, you can download it for free. No licence needed. Presently, many banks don’t charge for UPI transactions. However, the Reserve Bank of India (RBI) has said that charges for transfers made using UPI should not exceed NEFT charges. UPI is interoperable. This means that you can send money from your ICICI account to your friend’s HDFC account through the UPI app. You just need the unique address to transfer or receive money.