A call agent (CA) connects a IP telephone and a public switching telephone on the basis of a called-destination telephone number which corresponds to received reverse-charging service number from the IP telephone; a reverse-charging service control apparatus causes an exchange to stop charging; the CA and the reverse-charging service control apparatus calculate a charging information items, respectively; and generate a fee information by setting a charged party information so that a sum of fees in an IP network and a public switching telephone network may be charged to the called-destination telephone number, and transmit the fee information to an IP/PSTN charging management apparatus on a called destination side; and generate other fee information so that a fee in the network on a call origination side may be charged to a business company of called destination, and transmit the fee information to the apparatus on a call origination side.