PURPOSE: To prevent a large amount from being used illegally by checking whether or not a speech tariff exceeds an available limiting amount when calling is performed.
CONSTITUTION: Firstly, data base update information is received from a tariff calculator 13 or a data input device. When the update information shows the speech tariff, present total speech tariff data in accordance with a card number included in the update information is read out from an available amount data file 12. Thence. the speech tariff data this time included in new information is added on read out speech tariff data. Then, added speech tariff data is stored in an area in accordance with the card number of the available amount data file 12. Also, when the update information shows the update of a limiting amount, available limiting amount data is updated by rewriting. Also, when the update information shows the one other than the update of the limiting amount, the present speech tariff data in accordance with the card number included in the update information is cleared. By performing such processing, communication is prohibited when the speech tariff exceeds the available limiting amount.
SHIRONITA MASAKAZU
ARAMOTO MINORU
