To send a pre-transaction message, you must provide Google Pay with the shared
vendorPaymentTransactionId. Only merchants that have an existing billing
relationship with Google Pay or one of our billing partners have access to this service.
For most pre-transaction messages, the following flow is used:
- User places an order on your app or website and pays using Google Pay.
- Merchant receives Google Pay and UPI confirmation of payment.
- Merchant sends the message payload using the Communication API by providing the
- User receives a notification with the payload.
Example: Payment reminders
In this example, assume the user has already opened an account with mutual fund
company and made payment for the SIP (Systematic Investment Plan) using Google
Pay as payment method. Merchant can send a reminder message to the user about
the SIP payment due date using the
vendorPaymentTransactionId. This ID is
provided by the Payment Service Provider (PSP) to merchant for a successful
transaction by the user.
The user will receive a notification message in the Google Pay app with Top Up option to make payment using Google Pay. The payment reminder message shows the SIPs that user has purchased, the amount to be paid, and the due date.