Calling cards provide means to services that allow calls to be made from a telephone to be billed to a different telephone or credit card account.

Several forms of calling cards are in use today. Customers can purchase calling cards through their long distance provider, in which case the calls are billed to the customer's long distance account. Prepaid calling cards have a fixed balance that is paid in advance, and the card is valid until the balance is used up. Virtual calling cards are purchased via web-based services; customers receive a calling card number and associated PIN (personal identification number,) much like a prepaid card.