https://developer.apple.com/support/apple-pay-sandbox/ has a bunch of test cards you can use for sandbox testing. I was able to add a sandbox Visa, MasterCard, and Discover card successfully to my sandbox test account. But any time I try to add an American Express card (from the list), I get "Could Not Add Card" "Try again later or contact your card issuer for more information." Anyone else encountered this?
"Could Not Add Card" when trying to add an American Express sandbox test card
I am getting the same with all Amex cards... disappointing
Did you create a sandbox user account, as you might not be able to add test credit cards on your account which is not a sandbox account
Please fix being able to add Amex cards for Apple Pay testing.
6 years later and this is still an issue... it seems Apple is dragging their feet on Apple Pay sandbox support.