In order to improve a trailer coupling for motor vehicles, including a ball neck which is mountable on a rear part of a motor vehicle so as to be fixed to the vehicle by means of a ball neck carrier by way of a first end and on a second end carries a coupling ball, in such a manner that load carriers can be mounted and held securely in a simple manner, it is proposed that, for positioning a load carrier holding device, which is loadable onto the coupling ball and the ball neck, at least one first positioning body is arranged on the ball neck at a defined spacing from the coupling ball, that the at least one first positioning body is arranged on a ball neck portion of the ball neck which adjoins a ball attachment of the ball neck which carries the coupling ball and in particular, proceeding from the ball attachment, extends along the ball neck over a distance which corresponds to a maximum of one and a half times the diameter of the coupling ball, and that the at least one first positioning body extends transversely with respect to a development of the ball neck portion which carries said positioning body and away from said ball neck portion.