25th September 2021

Let's quickly reiterate the payment flows of UPI we discussed in Day 11: UPI, entities involved.

Based on who initiates the transfer:

  1. Push: Payer initiates the transfer to payee
  2. Pull: Payee requests the payer to transfer

Based on the no. of parties involved excluding NPCI, there are few models: Two party model, Three party model, Four party model.

Push Payment flow; Four party model

Push Payment flow; Four party model

Consider a P2P or peer to peer transaction of amount ₹100 from Mona to Krishna. Mona uses Paytm for most of her UPI payments and has a savings account in HDFC, while Krishna uses GPay and has a bank account in SBI. These are fictional examples just to understand the flow.

Four party model entities

Following are the steps involved in the above UPI Push transfer:

  1. Payer (Mona) initiates the transaction by entering Payee (Krishna's) VPA, amount and the UPI Pin on the UPI payment app (Paytm)
  2. Payer PSP (Paytm) receives the request and transfers it to NPCI
  3. NPCI forwards the request to Payee PSP (GPay) for address verification and authorisation
  4. Payee PSP resolves the request and provides the account details of the payee to the NPCI server
  5. NPCI checks with the Remitter bank (HDFC) and debits the fund from the payer's account
  6. Remitter bank sends response to NPCI
  7. NPCI sends a credit request to the beneficiary's bank (SBI) and credits the fund to the payee's account