Your customers can easily change their payment methods in the customer portal (https://help.kinnovis.com/en/articles/8009928-update-payment-method-in-the-customer-portal), but sometimes they need help with that, or ask the operator to do it. To make this process short, the operator can also adjust the payment method for a booking within the manager.

Open the booking you want to update the payment method for, click on actions and find the action "Update payment method"

A popup will open that offer you all kind of options to adjust how your customer pays for the booking. Once saved, all new invoices will be charged using the newly defined payment method.