I pay my X credit card bill through my Y bank. The payee information, i.e. the X credit card number, was added many years ago. Every month when I make the payment, I simply select the payee, enter the amount, that's it.

Just had a look at the payee management page of Y bank, and realized that the credit card number was the old one. There was a time when X changed my credit card number. However, the old number was still associated with me and still effective for payment. The payment has been working fine!

Just for your information.