Originally Posted by
drminn
A business can post temporary charges and put a "hold until confirmed" on the charges. I am wondering if Delta does that, hotels do it all the time for their incidental charges. Restaurants do it as well to let you add the tip.
When you buy a ticket, they authorize your card for the amount. Then, after the risk-free cancellation period has passed, they capture (charge) the amount to your credit card.
They don’t authorize any additional amount above the ticket cost, because it’s not going to change. If you later buy an upgrade or something like that, it’s a whole new charge. And if you cancel the ticket within the risk-free period, the authorization simply drops off and your card is never actually charged.