When I am processing a normal payment then adding a card on file, it is easy to check for duplicates as the CreatePayment api result contains the card fingerprint. I can then check that fingerprint against the cards the user currently has on file and only create the card if it is new.
Is there a way to get the fingerprint of a card from the nonce without creating a payment but before calling CreateCard? I couldn’t find any reference to the fingerprint in the TokenResponse from the Web Payments Api. None of the Card api’s take a card nonce.
Most likely when a user updates the Card on File they will be using a unique card, but it would be still be nice to check for duplicates on the off chance they used the same card again.