The present invention refers to real estate intermediation information service system and method relates to, offerings that commodity non-store-store the designation of a dealer module and designated dealer, offerings of certified copy for analyzing certified copy analysis module and, offerings transaction safety to determine whether the safety light class determination module element is provided to said offerings transaction according to certified copy and an analysis result of said determination result class safety light and designated non-store transmitting and to a terminal of a dealer, offline last two numbers to send a request for on-line mobile without through is provided as the first real estate intermediation information non-store the recording operation..