There is provided an identifier authenticating system in which information requesting users can share all the predetermined information held in a plurality of information providing servers. In the identifier authentication system, when an identifier holding user 18 presents an identifier to an information requesting server 16, the information requesting server 16 asks a location management server 14 about a location of the information providing server 15, the location management server 14 returns confirmed IP address of the information providing server 15 to the information requesting server 16 based on the location information, and the information requesting server 16 utilizes the confirmed IP address to access the information providing server 15 corresponding to the confirmed IP address, and receives predetermined information corresponding to the presented identifier and a disclosure level from the accessed information providing server 15.