The Stripe payment gateway service (which WHMCS supports) has an awesome feature called "Smarter Saved Cards" that will automatically update a customer's card, if the bank replaces the card (new card number), or even if just the expiration date has been updated. You can read more about this feature here:https://stripe.com/blog/smarter-saved-cards
As their site indicates, "over half of the cards stored with Stripe in the last year would stop working if they weren’t updated."
This would be very helpful to hosting providers, as we all know that we sometimes lose customers simply because their credit cards expire or stop working for charging fees. I believe we could increase customer satisfaction and reduce churn, by implementing "Smarter Saved Cards"
Stripe says "The customer.source.updated webhook will fire if your customers’ info changes." -- perhaps this is something that WHMCS could be looking for, and also update the info in WHMCS, such as expiration date, or last 4 of the card?
Thanks for considering this request.