There is disclosed an invention for generating contract information for an image forming apparatus for which the user is going to conclude a contract. The history information of an image forming apparatus used by the user and having a contract history is stored and managed in correlation with the user. Such management is executed in a center server capable communication with the image forming apparatus through a predetermined communication channel. The above-mentioned information includes contract term, machine type, number of print outputs etc. of the image forming apparatus. Also the image forming apparatus to be managed includes that currently contracted and that contracted in the past. In case the user wishes to conclude a new contract for an image forming apparatus, new contract information is generated according to the history information managed by the center server in correlation with the user. This invention provides a system capable of realizing the foregoing.