PURPOSE: To quickly retrieve dormant account information to not only improve the efficiency of business work but also reduce the burden on each business office.

CONSTITUTION: When dormant account information having a key part specified on the host side is recorded in a recorder 5, an index register 2a where the key part and the address for recording to the recorder are related to each other is generated. When for instance, payment is requested from a telephone, a facsimile, or a terminal equipment 6a of the respective business office, information of the key part is inputted from a terminal equipment 3 on the device main body side to specify the address from the index register, and dormant account information is taken out from the recorder, and required payment processing is performed, and the result is returned to the request source of the pertinent business office.