To provide a rate-managing system, with which the load of line rates is reduced and the risk of trouble in work operation is eliminated, to be used for a specific charging system utilizing a communication line.

A cutting right purchase program 13 is started, a client 7 is connected via the Internet 25 to a server 27, and a cutting right area is purchased. When cutting a wind film with a cutting plotter 5, a cutting program 11 is started by the client 7, and object car type information is inputted. When the area of the wind film for input target car type is equal to or less than the remaining cutting right area, under the control of the cutting program 11, the cutting plotter 5 is operated.