PURPOSE: To pay a proper charge to a party offering service by dialing a special number after the insertion of a magnetic card so as to identify the special service.

CONSTITUTION: When the special service is desired to be received, the magnetic card 2 is purchased from a center 9 for charged telephone system and makes a dial by inserting the card to a telephone set 1. An exchange detects a call by a subscriber circuit 3 and a common controller 5 decides the special service. Then whether or not the magnetic card 2 is used is identified via the subscriber circuit 3. When a destination number (number of telephone set 8) is received from the telephone set 1, the common controller 5 inquires about the destination number to the service center 9 via a common line signal device 6 and when the number is a registered number, charging information is transferred to the exchange. Then the telephone sets 1 and 8 are connected and a charging signal is transmitted finally.