A proxy terminal, comprising: a terminal group information generator unit configured to generate terminal group information which includes a user terminal identifier and a network identifier of the proxy terminal as a pair; and a terminal group information transmitter unit configured to transmit, to a server apparatus, the terminal group information generated by the terminal group information generator unit, wherein the terminal group information generator unit is configured to acquire the user terminal identifier and a terminal group information transmission destination network identifier, from proxy terminal log in contents which is acquired by a user terminal from the server apparatus and includes the user terminal identifier and the terminal group information transmission destination network identifier as information in the contents, and to generate the terminal group information which includes the acquired user terminal identifier and the proxy terminal network identifier as the pair, and the terminal group information transmitter unit is configured to transmit the terminal group information generated by the terminal group information generator unit, to a terminal group information transmission destination server apparatus which is described in the terminal group information transmission destination network identifier acquired from the proxy terminal log in contents, whereby the proxy terminal further comprises: a communication data receiving unit configured to receive communication data transmitted from the user terminal or the server apparatus; and a communication relaying unit configured to relay the communication data between the user terminal and the server apparatus, based on communication path information which is included in the communication data and indicates that the proxy terminal is set as a relay point. a terminal group information generator unit configured to generate terminal group information which includes a user terminal identifier and a network identifier of the proxy terminal as a pair; and a terminal group information transmitter unit configured to transmit, to a server apparatus, the terminal group information generated by the terminal group information generator unit, wherein the terminal group information generator unit is configured to acquire the user terminal identifier and a terminal group information transmission destination network identifier, from proxy terminal log in contents which is acquired by a user terminal from the server apparatus and includes the user terminal identifier and the terminal group information transmission destination network identifier as information in the contents, and to generate the terminal group information which includes the acquired user terminal identifier and the proxy terminal network identifier as the pair, and the terminal group information transmitter unit is configured to transmit the terminal group information generated by the terminal group information generator unit, to a terminal group information transmission destination server apparatus which is described in the terminal group information transmission destination network identifier acquired from the proxy terminal log in contents, whereby the proxy terminal further comprises: a communication data receiving unit configured to receive communication data transmitted from the user terminal or the server apparatus; and a communication relaying unit configured to relay the communication data between the user terminal and the server apparatus, based on communication path information which is included in the communication data and indicates that the proxy terminal is set as a relay point. a communication data receiving unit configured to receive communication data transmitted from the user terminal or the server apparatus; and a communication relaying unit configured to relay the communication data between the user terminal and the server apparatus, based on communication path information which is included in the communication data and indicates that the proxy terminal is set as a relay point.