If you have recurring payments or a cards-on-file set up with a merchant(s), if account changes are made to your account—for example, a debit or credit account number has been changed or an expiration date has been updated—you may forget to advise merchant(s) about the changed account information, which could cause recurring payments to be declined. The Mastercard ABU Service allows the updated information to be provided to participating merchants on your behalf resulting in fewer declines. The service provides a convenience to you so you do not have to contact each merchant with your updated card information.