If you’ve added a new payment method to your Microsoft Azure billing account, and try to remove another existing credit card, you might receive the following error message.
One or more of the selected payment method(s) is in use and cannot be deleted.
This error message might be appearing because the existing payment method is still configured as your default payment method on one or more Microsoft Azure subscriptions. Head over to your Billing Properties, and update your default payment method, and then try to go back and delete your old payment method. You should see a successful removal of your old payment method from the billing account.
In case you have trouble locating it … the default payment method is buried under Subscriptions –> Settings / Billing Properties –> Billing Account –> Settings / Payment Methods. Once you find it, there will be an option to select your default payment method, at which point your old payment method should be “unlocked” for deletion.