Originally Posted by maledictis

This was happening to me, too. Then I discovered why - and it was my fault. My CC expiration date had passed, so when I got to that final purchase step, the transaction failed. Now that I've updated my CC in my profile, it's smooth sailing again.

Not saying that's what's going on with your partner's experience, but easy enough to check.

But it WOULD have been helpful if, when the transaction failed, delta.com had a more meaningful error besides "something somewhere didn't work." Something to the effect of "Hey, dummy. Your CC expiration date has passed. Fix it." would have been a lot more useful.