Physical, offline phone cards are credit card-sized cards used to pay for telephone services. There are essentially two types of phone card - prepaid (also referred to as a stored value card) or those that operate using a credit card style system (remote memory). The most common type of phone cards are the pre-paid version where the card is pre-charged with a fixed amount from which the cost of calls made is deducted until the card runs out or, with certain types, topped up. Pre-paid phonecards are disposable. When the balance is exhausted you simply throw away the old card and buy a new one. Credit card style phone cards come with a special PIN that allows callers to charge calls to a landline telephone account.

Since their introduction in Italy in the 1970s prepaid phone cards have become hugely popular and now used all over the world. Their success is hardly surprising given that phone cards offer a low cost and convenient method of communicating.