Why Do Cashiers Sometimes Rub the Magnetic Strip of a Malfunctioning Debit or Credit Card With Their Clothes?
A credit or debit card will fail to swipe correctly for one of three reasons. First, something has permanently interfered with the magnetic strip on the card, so that the computer cannot read it. The cashier will have to type in the number manually, and a new card will probably need to be issued. Secondly, the machine is faulty