To provide a selling method for rationalizing the selling procedure of a portable telephone and capable of preventing the increase of costs even when the number of commodities to be sold is increased.

Personal identification and preliminary examination/inquiry are previously executed between a purchase application terminal equipment 101 installed in a store group 1 and a customer management system in a communication agency 6 by using an on-line system and a payment slip is printed out. When a charge is received in a register, a receiving terminal equipment transmits receipt completion informing data to a receipt managing computer system 504, which executes opening requesting processing. When an operation method is not clear, the system 504 inquires a CTI center by using a transceiver of the terminal equipment 101.