Unified Payments Interface (UPI) is an instant payment system developed by the National Payments Corporation of India (NPCI), an RBI regulated entity. UPI is built over the IMPS infrastructure and allows you to instantly transfer money between any two parties’ bank accounts. UPI is a single platform that merges various banking services and features under one umbrella. A UPI ID and PIN are sufficient to send and receive money. Real-time bank-to-bank payments can be made using a mobile number or virtual payment address (UPI ID)
For example:- in BHIM app UPI ID is shown as XXXXXXXXXX@upi, and in Paytm it’s XXXXXXXXX@paytm. You can however create your unique UPI ID as well. The process is the same across all platforms with the first step being providing your registered mobile number.
A debit card is mandatory to set the UPI PIN, under the existing mechanism.A customer must key in debit card details to receive a one-time password (OTP)on his phone to log into the system. As such, customers who have bank accounts but do not have debit cards cannot use the homegrown payments network.
Sometimes, there can be delays in payments, it takes up to 48 hours for the money to get back to your bank account. The UPI money transfer limit is currently Rs 100,000, which you can send to anyone through the mobile app.