There are a number of ways to update your customers payment details. You can do this in app by either sending your customer a payment details request email or by entering the details manually. You can also allow your customers to easily update their own payment details at any time using the self-service account management modal.
The account management modal functions in the same way as our checkout modal, in that it must be embedded into your website. You can read more about how to do this this here.
Once they've logged in to their account, they simply need to choose Update payment details from the menu, once they've logged in, and follow the steps to make the changes.
Configuring the account management modal
When you're configuring your self service modal, you'll need to decide which of the elements of their subscription you'd like them to have access to manage. You can do this by navigating to Settings > Configuration > Checkout and account management settings > Self-service (tab). Once you're on this page you'll see the option to toggle on or off each of the account management elements. To make sure your customer have access to update their payment details, you'll need to make sure that this is toggled on.
