In majority of the cases the expired saved card will still continue to work. This is a smarter card save feature from our payment processor Stripe. Therefore, update the expiration date of a saved card is not required!
If the card number change, we will send your recurring donor a email to ask her to re-enter the card number. If an expired card doesn't charge, the same step is followed. Each donor has a donorbox.org donor login that they can use to update the payment information at any time.