PURPOSE: To attain credit payment of a talking charge by connecting the titled telephone set to a credit center based on card information read by a credit card to use a credit processing means thereby applying on-line processing to a talking charge.

CONSTITUTION: A control section of a telephone set consists of a microcomputer comprising a CPU10 and a storage circuit section 11, and a network control unit/MODEM12, a keyboard section 13, a magnetic card section 14, a charge control section 15 and a display circuit 16 are connected to the CPU10. Further, the control section consists of a handset connected to the MODEM12 and giving/ receiving a voice signal with a telephone set being a talking destination through a public telephone line 9. The information of a credit card read by the reader section 14 is fed to the CPU10, the check of credit is attained via the line 9 and when the credit result is OK, the talking charge obtained by the CPU10 is subjected to on-line processing by the credit after talking.