Trailer coupling

The invention relates to a coupling device for a motor vehicle (K), with a coupling arm (11), wherein the coupling arm (11) is mounted on a vehicle holder (20; 420; 220) by means of a bearing between a use position (G) and a non-use position (N), wherein a bearing base body (33) of the bearing is arranged fixedly on a vehicle holder part (21; 421; 221) of the vehicle holder (20; 420; 220), on which a bearing element that supports the coupling arm (11) is movably mounted, wherein the coupling device has a fixing device for fixing the coupling arm (11), wherein the fixing device has a fixing element (60) movable between a fixing position (F) and a release position (L) and a fixing drive (80) for driving the fixing element (60), characterized in that the fixing drive (80) is arranged at least partially in an interior space of the bearing and the at least one fixing element (60) is arranged outside the bearing and is drivable by the fixing drive (80) from the interior space of the bearing element.