A tax of 12% of the sales price is imposed on the first retail sale of the following articles, including related parts and accessories sold on or in connection with, or with the sale of, the articles.
- Truck chassis and bodies.
- Truck trailer and semitrailer chassis and bodies.
- Tractors of the kind chiefly used for highway transportation in combination with a trailer or semitrailer.
A truck is a highway vehicle primarily designed to transport its load on the same chassis as the engine, even if it is equipped to tow a vehicle, such as a trailer or semitrailer.
A tractor is a highway vehicle designed to tow a vehicle, such as a trailer or semitrailer. A tractor may carry incidental items of cargo when towing or limited amounts of cargo when not towing.
A sale of a truck, truck trailer, or semitrailer is considered a sale of a chassis and a body.
The seller is liable for the tax.
Read more on the Retail Excise Taxes on Heavy Trucks and Trailers at irs.gov