Telephone card

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A telephone card, calling card or phone card for short, is a small plastic card, sized and shaped like a credit card, used to pay for telephone services. It is not necessary to have the physical card except with a stored-value system; knowledge of the access telephone number to dial and the PIN is sufficient. Standard cards which can be purchased and used without any sort of account facility give a fixed amount of credit and are discarded when used up; rechargeable cards can be topped up, or collect payment in arrears. The system for payment and the way in which the card is used to place a telephone call vary from card to card.

Cards known as remote memory cards have a PIN associated with a specific land-line telephone account; calls using the card are billed to the associated account.


Stored-value phone cards

In stored value, called so because the card itself contains the balance available, the balance is read by the public pay-phone machine when it is inserted into the machine's card reader. This is superficially similar to an automated teller machine at a bank, but a stored value card is more closely analogous to a change purse than an ATM card. While ATMs (as wells as the remote memory systems discussed below) use your card merely to identify your account and record changes in a central database, stored value systems make a physical alteration to the card to reflect the new balance after a call. Used primarily for pay phones, stored value systems avoid the time lag and expense of communication with a central database, which would have been prohibitive before the 1990s. There are several ways in which the value can be encoded on the card.

The earliest system used a magnetic stripe as information carrier, similar to the technology of ATMs and key cards. The first magnetic strip phone card, manufactured by SIDA, was issued in 1976 in Italy.

The next technology used optical storage. Optical phone cards get their name from optical structure embossed inside the cards. This optical structure is heated and destroyed after use of the units. Visible marks are left on the top of the cards, so that the user can see the balance of remaining units. Optical cards were produced by Landis+Gyr and Sodeco from Switzerland and were popular early phonecards in many countries with first optical phonecards successfully introduced in 1977 in Belgium. Such technology was very secure and not easily hackable but chip cards phased out the optical phone cards around the world and the last Landis+Gyr factory closed in May 2006 when optical phonecards were still in use in few countries like Austria, Israël and Egypt.

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