PURPOSE: To contrive the impartial allotment of expense by updating service score based on the service score calculated in accordance with the frequency in use of common facilities by a customer, and calculating the allotment ratio of every store to the amount of money for using of the common facilities based on these scores.

CONSTITUTION: Every time the customer does his shopping or uses the common facilities, the service scores are calculated at a store terminal 2 or a common facility terminal 3, and the service scores of a card 1 are updated. Further, at a central processing unit 4, the allotment ratio of every store to the amount of money for using of the common facilities is calculated based on the service scores transmitted from the store terminal 2 and the common facility terminal 3. Accordingly, the allotment ratio can be calculated quickly with any manual aid, and besides, a result becomes impartial to the customer and the store. Besides, a customer identification number and the service scores are recorded on the card 1, and the service scores are updated every time the customer does his shopping or uses the common facilities.