There is provided a prepaid system able to reduce inconvenience caused by issuing and using a large number of prepaid cards. A communication terminal purchases a prepaid number related to a predetermined amount of money by using a deposit of the communication terminal made in advance and managed by the prepaid system, and pays for its communication charge using the predetermined amount of money related to the prepaid number. Or, the communication terminal uses a prepaid count set in advance and managed by the prepaid system to pay for its communication charge before or after the communication made by the communication terminal. Or, the communication terminal assigns a part of its prepaid count managed by the prepaid system to other communication terminals to pay for their communication charges before or after the communications made by the other communication terminals.