Ever wondered why the numbers on your credit card are embossed, raised characters rather than just printed on the card?
To sell you something using a credit card, retail businesses used to have this procedure. They would put your credit card into a device, place a multi-part carbon form over the card, and slide a heavy slider across the card to manually imprint details of the sale. The customer then signed the form. The retailer checked that the signature on the form matched that on the back of the card. (Though they could be surprisingly lax about this.) The business kept a copy of the transaction, so did the customer, and a third went off in the post to the payment-processing company.
Using an imprinter may have been more time-consuming than waving a “contactless” card at a terminal, but the method had its benefits.
The retailer could make a sale even in the event of total power failure. The customer who wanted a torch to help deal with the blackout would be happy. Similarly, the customer looking for a tent after an earthquake.
You had a physical record of the sale, too, which was useful in the event of a dispute about who had bought what and when.
The big disadvantage, though, was that the imprinter took a copy of everything a potential fraudster could possibly need to make some criminal transactions: the customer’s entire credit card number (not just the last four digits as you see on electronic receipts), expiration date and signature. All on one bit of paper. Easy enough to pick up the phone, armed with that information, and merrily start ordering things.
Gradually, the slips of paper gave way to magnetic stripes, point-of-sale terminals, electronic verification of card numbers, and instant checks that the customer wasn’t going over the spending limit. We invented CCV security codes, magnetic strips, chips, and 4-digit PIN numbers. Today, transactions go through like lightning, not via the postal system
Plenty of businesses still hang on to their imprinters, though. You can still buy them, as well, as well as the forms to go in them. Just in case, you know, the lights do all go out.