To improve convenience for the user of a communication terminal equipment and to simplify control in a communication center, in a communication system made into a prepaid charging system.

The communication center for connecting a line between portable telephone sets, controlling a base station and controlling and managing a charging processing or the like is provided with a data base for recording the balance of a prepaid communication charge at all times, together with the ID code of a subscriber. The controller of the communication center retrieves the balances of the prepaid communication charges on a call origination side and a call termination side (S1 and S4), when a call is terminated, and when even one of them is negative or zero, the call origination (S2 and S5) is denied and reports that effect to a call origination side (S3 and S6). When both balances are positive, communication is made possible (S7), and after the communication is ended, a communication charge corresponding to communication time is charged (the balance is subtracted) from the prepaid communication charge on the call origination side (S8). The balance of the prepaid communication charge is reported to the portable telephone set on the call origination side (S10 and S11).