Prepaid phone cards differ in rates, prices and services providing local and international coverage. Since prepaid phone cards differ in features, it is important to select one which suits one's needs
Today’s international calling cards are activated either by entering a pin number into a toll free number, or by placing a call from a number that is pre-registered. A secret pin number can be used to activate some cards. Many cards are prepaid and will automatically hang up once you have used the allocated amount of time. But there are some calling cards that allow you to extend the time of call by paying extra, even after the allocated amount is used up.