A Utah motor vehicle bill of sale, known as Form TC-843, is an official document that provides proof that a vehicle has been sold in the State of Utah. Motor Vehicle Bill of Sale (Form TC-843)– Can be used to prove the sale and purchase of either a motorcycle or automobile in the state of Utah.Create a Utah bill of sale form to document the transfer of ownership of a vehicle or another piece of personal property. 1. Obtain the Utah State Motor Vehicle Bill of Sale form. Although not legally required, the Utah DMV advises and provides private sellers with a bill of sale (form TC-843) to use when selling your car on your own. The state provides Form TC843 for use as a bill of sale on vehicles sold in Utah.