Why the payment method cannot be changed
Once an order has been placed and a payment session has been completed, the payment method is locked to that transaction.
Kustom does not support switching to a different payment method on an existing order.
How to help the customer change payment method
There are two options if a customer wants to change the payment method.
The customer can place a new order in your checkout.
You can generate a new payment link to the customer based on an existing order. The customer can then fulfill the order with the payment method of their choosing.
Important: Make sure you do not refund or cancel the existing order until you verify that the new order is placed.
Use case example
Question: A customer is asking a Merchant if it's possible to change payment method for an order that has already been placed.
Answer: No, but it is possible to send a payment link and let the customer choose another payment method for the duplicated order.
Question: A customer is asking a Merchant if it's possible to pay an invoice using their card.
Answer: No, but it is possible to send a payment link, let the customer choose card, capture that order and remove the invoice version of the order.