An object is to provide a technique capable of displaying appropriate information on a passenger display unit used for a passenger other than a driver. An in-vehicle information terminal includes an in-vehicle device I/F and a controller. The in-vehicle device I/F is capable of communicating with an in-vehicle device having RSE monitors, and is capable of obtaining terminal position information indicating positions of communication terminals in a vehicle. The controller associates the RSE monitors and the communication terminals with each other, based on pre-registered display unit position information indicating the positions of the RSE monitors in the vehicle, and the terminal position information obtained by the in-vehicle device I/F.