The invention relates to a trailer coupling (10) for a motor vehicle comprising a coupling arm (11) for attaching a trailer or for carrying a load carrier, and comprising at least one sensor (40a, 40b) for detecting a deformation, caused by a load engaged on the bearing element (60, 62), of a bearing element (60) of the trailer coupling (10), in particular of the coupling arm (11) or a carrier arrangement for carrying or holding the coupling arm (11), wherein at least one recess (21) is provided on the bearing element (60) for the at least one sensor (40a, 40b), wherein the at least one sensor (40a, 40b) is provided for measuring a spacing of reference surfaces (25, 26) of the at least one recess (21). According to the invention, for the trailer coupling (10), the reference surfaces (25, 26) move toward one another or away from one another during a deformation of the bearing element (60-62) and extend in a transverse manner in relation to a support section (31) of the bearing element (60-62) which deforms during stress applied by the load and/or are free from a flow of forces (K) through the support section (31) of the bearing element (60-62), said power flow being transmitted from the support section (31) during the stress applied by the load engaging on the bearing element (60-62).