DOT Number
What is dot number? A DOT number is a unique identifier the Department of Transportation assigns to commercial motor vehicles operating in interstate commerce.
Full definition
The USDOT number tracks safety records, inspections, audits, and crash investigations across the carrier's lifetime. Any vehicle hauling federally regulated cargo across state lines, or weighing more than 10,001 lbs in many cases, must display the number on both sides of the cab.
DOT numbers are free to obtain and remain attached to the carrier — not the truck — for life. Updating biennially via the MCS-150 form is mandatory; lapses lead to deactivation.
DOT and MC numbers are often confused. DOT is the safety identifier; MC is the operating authority. Some carriers (intrastate, certain agricultural haulers) need only DOT and not MC.