eli5 How did Credit/Debit Cards work before Chip & Pin Machines?

Question

eli5 How did Credit/Debit Cards work before Chip & Pin Machines?

In: 64

Answer 1

Originally, the merchant had a small clipboard-like device with a roller. They’d place the card down, and a special piece of paper on top of it, then run the roller overtop which would imprint the card numbers onto the paper. They’d save all these records and then mail them to the bank.

Then the information was contained in a magnetic strip like you see on the back of gift cards today which could be read by an electronic card reader when swiped.