Used box trucks can be found at companies like U-Haul and eBay. They are either sold directly by the company that used to use them or sold by an independent party seeking to profit off of their used truck.
Because U-Haul utilizes box trucks regularly for renting, they sometimes have a surplus of trucks that are sold to interested parties. As of 2015, they have four different sizes of cargo boxes for the rear of the trucks with a cab and chassis option available as an alternative. Availability varies depending on the area the customer is from, requiring a search using the online search functions on the U-Haul official website.
Box trucks that are offered by independent sellers are listed on eBay. Although eBay offers a wide variety of choices depending on when a user searches, some of the sales are auction-based, making them riskier purchases compared to buying directly from a company like U-Haul.
Following the middle of this road is Penske, which is a company that offers used trucks in a wide range of makes and models. This company has its own listing that allows customers to search for locally-maintained used box trucks for purchase. Because Penske has a wider range of business in the automotive industry, it has more types of box trucks available.