To provide means for automatically selecting the charge for communication/telephone call being regarded as the lowest charge among conditions selected by a user of various fixed communication terminals, mobile communication terminals, portable terminals, network terminals, and the like, and providing a service at a charge regarded most advantageous by altering the content of contract for each individual user at any time without generating any penalty from each electrical communication provider with regard to contact and paying method.

A program for managing the charging system presented by electrical communication providers centrally in a server, automatically selecting an amount of money regarded to be lowest by combining services satisfying conditions of users of various fixed communication terminals, mobile communication terminals, portable terminals, network terminals, and the like, and rewriting the information of the charging system or the using conditions of a user every time when it is altered is built in a storage device.