PURPOSE: To enable a call many times by one telephone card by designating a charging destination when there is no call frequency in the telephone card.

CONSTITUTION: When requesting connection designating the charging destination from a public telephone set 5, a telephone card 1 is inserted to the public telephone set 5, and the number of a callee is dialed. At such a time, however, '*'is finally dialed. At an exchange 11, the three kinds of information such as a charging destination telephone number 2, personal code number 3 and use possibility symbol 4 in the telephone card 1 are analyzed together with the line number of a caller and when the analyzed result shows that charging can not be executed to the designated charging destination, a busy tone(BT) is transmitted to the caller. When the charging is enabled, however, the callee is connected similarly to the normal exchange operation. Thus, even when there is no rate remaining in a card in the middle of the call, the call can be continued.