Abstract: In order to provide a trailer coupling for motor vehicles, in particular passenger vehicles, comprising a coupling ball, a ball neck, one end region of which is angled and bears the coupling ball, and a drive comprising a drive motor, by means of which the ball neck is movable with the coupling ball from an operative position into a rest position and vice versa, such that this operates as safely as possible it is suggested that a control means be provided for operating the drive, this control mans allowing either movement of the ball neck or traveling of the motor vehicle.