>For instance, you may be able to use your credit card at a store even if their phone line or internet connection breaks down.
Actually, no. No approval code (which is obtained from the network), there is no purchase.
Actually, no. No approval code (which is obtained from the network), there is no purchase.
The transaction is stored, and fowarded later. It's a variant on the Card Number + Impression that used to be common place 20 years ago, and Card Number + CCV that is still common place in locations with intermittent/no connectivity.
The prime example of this being done electronically is on planes, they have been accepting credit cards a large number of years before connectivity was possible.
Don't forget that the banks make their money from ATMs off the transaction fees, so if a foreign customer's bank is unreachable at that moment, they may still take a chance and give them their money (plus charge them the $4).
Do you work in banking and know about this, or are you making assumptions about how payment terminals work?