A vehicle authentication method, a recording medium storing a program, a terminal device, and a vehicle authentication system which may raise security level on vehicle authentication by a user are provided. In the vehicle authentication method, the terminal device acquires a vehicle authenticator for authentication of a reserved vehicle, sends a reference vehicle a request for a vehicle authenticator for authentication of the reference vehicle, and determines whether the vehicle authenticators of the reference vehicle and the reserved vehicle coincide. Then a message that the reference vehicle is the reserved vehicle is displayed on the display unit upon determination that the vehicle authenticators of the reference vehicle and the reserved vehicle coincide. And a message that the reference vehicle is not the reserved vehicle is displayed on the display unit upon determination that the vehicle authenticators of the reference vehicle and the reserved vehicle do not coincide.