I received a new Discover card to replace an old one. I went into the few websites that store my info in order to change the expiration date. After doing so, I went to Safari > Preferences > Autofill and found that Safari had already changed it. How did this happen?

Does Safari communicate with Discover? Does Safari know when I changed the date in a website? It seems to me that this is a breach of privacy.

Safari may very well have picked up on the changes as you made them on those websites.

I've never used AutoFill and can't experiment.

I'm thinking that the occurrence may have been similar in nature to AutoFill's recognizing when you enter a password that differs from the one previously saved for a particular website.

Although it is rude of Safari to have made the change without advising you.

Do you use Apple Pay? If so, new credit card numbers are automatically updated there, and from that update it is a short hop to Safari.

If not, …?

No, I don't use Apple Pay.

You may be on to something, Artie. Here's a possibility: Epson's website stores my CC information (I order ink and paper reasonably frequently) and I went to that site to update my CC info. Unlike other sites, Epson does not allow you to edit the info. Instead, you have to delete the old CC and start anew.

Consequently, I deleted the old CC and used Autofill to enter the card number and expiration date. Then, I manually corrected the date that had been entered. It's possible that Autofill updated itself at that point with the new expiration.

Thinking back I realize I have encountered two differing situations with credit cards data in Safari...

1. The site requests a credit card number and I manually fill in the information with a new or different card number and Safari automatically creates a new credit card entry in addition to the old one
2. A site requests a credit card and I select one from the list stored in Safari but update the expiration date and Safari updates the existing credit card entry.

This leads me to believe Safari's handling of credit card data has more intelligence behind it than I had originally given it credit for. I also realize there are several other possible scenarios and it is inconvenient to test them all. However, in every case it would be nice if Safari asked if I wanted to create a new credit card or update an existing entry. FWIW I am going to submit a request to that effect.

You can add my name to that request. I don't mind convenience, but it has to be with my knowledge and approval.