Abstract: A locking device for selectively lockingly engaging a towing element of a trailer to block coupling access to the towing element. The locking device includes a housing defining a towing element receptacle, an engaging element having an engaging portion and an actuating portion for selectively engaging a towing element disposed within the towing element receptacle, a locking compartment adapted to house the actuating portion of the engaging element, a locking compartment cover, an actuating tool coupled to the locking compartment cover and adapted to cooperate with the actuating portion of the engaging element, a locking chamber for receiving the actuating tool when the locking compartment cover is in a closed position, and a lock for selectively locking the actuating tool within the locking chamber and locking the cover in place.