Trailer hitches can be sold as kits for self-install or they can be installed by the manufacturer. Many new trucks and SUVs come with hitches already installed and wired. Professional installation allows for wiring to be hidden inside the trailer hitch, and thus better provided. Gooseneck hitches are particularly hard to install, requiring drilling through the bed of the truck. However, they are essential for very large and heavy trailers such as larger campers or horse trailers.
Used hitches are commonly sold, being removed from vehicles prior to sale or scrapping. Although this offers a significant discount, there is a certain luck involved in finding a hitch suitable to the customer's need. Adaptors and extenders may be used to allow for a different sized receiver and socket. Custom hitches are commonly sold.
Installation of bike racks and roof racks is a common side line of hitch installation companies. They may also sell trailer accessories such as load chains and spare wheels. Hitch parts, including bars, bolts and wiring parts are also important. Hitch covers are particularly valuable when a trailer is used only seasonally, common with boat trailers and sometimes motorcycle trailers. Utility trailers generally require much smaller hitches, but all hitches are mounted on the vehicle by some means. Removing a hitch can take time.
Trailer hitch installers may also advise on towing techniques and maximum tow weights. In some cases, they may recommend specific types and brands of trailers, especially utility trailers. They also do repairs, including replacing bars and redoing wiring. Although it is quite possible to install a simple hitch as a DIY project and kits are available online, it is likely that business for installers will remain good for the forseeable future.