Carrier types

Car hauler authority: cargo insurance, length rules, and filings

Q: Do I need an MC number to haul cars?

Hauling vehicles for hire across state lines is regulated interstate commerce. Companies that transport passengers in interstate commerce for compensation, or transport federally regulated commodities owned by others (or arrange their transport) for compensation in interstate commerce, need interstate operating authority in addition to a USDOT number.

Car haulers follow the same federal authority steps as any for-hire carrier. The delta sits in the insurance file and the trailer: no federal cargo minimum exists for vehicle transport, so brokers and contracts set your cargo limit, and federal length rules give auto transporters their own floors.

By Evan Reid, Founder of Haul Handbook · Updated Sep 7, 2026

The authority steps are the standard ones

Companies that transport passengers in interstate commerce for compensation, or transport federally regulated commodities owned by others (or arrange their transport) for compensation in interstate commerce, need interstate operating authority in addition to a USDOT number. A car hauler checks every box on that list, so the path runs through the same sequence as any startup carrier: the walkthrough in how to get your own authority applies unchanged, starting with the MC number. What changes is what you insure and what you tow.

Cargo insurance: the contract sets the number

FMCSA requires a cargo insurance filing (form BMC-34) only from household goods carriers and household goods freight forwarders. An auto hauler files no federal cargo form, and no federal rule sets a cargo dollar minimum for vehicle transport. Cargo limits for car haulers come from contracts instead: brokers, dealers, and auction terms state the coverage they expect, sized to the value of the vehicles on the trailer.

Open and enclosed operators price this differently for one reason: an enclosed load of six vehicles can carry several times the value of an open load of the same count, and the contract limit follows the value on the deck. The same contract-driven cargo logic shows up in reefer trucking, where shippers set the cargo bar instead of a regulator.

Liability: filed for you, at the property-carrier minimum

For liability filings a for-hire car hauler is a property carrier of non-hazardous freight. The standard BIPD minimum for vehicles at 10,001 pounds GVWR and up applies, filed by the insurer on form BMC-91 or BMC-91X.

Public liability (BIPD) minimums for non-hazardous property carriers, from the federal spine.
Operation	Vehicle	Liability minimum
For-hire property carrier, non-hazardous	GVWR under 10,001 lb	$300,000
For-hire property carrier, non-hazardous (general freight)	GVWR 10,001 lb or more	$750,000

Who files what, and in which order, lives in the insurance filings guide.

Length rules written for auto transporters

Automobile transporters count as specialized equipment under federal size rules and may carry vehicles on the power unit. No state may set an overall length limit under 65 feet for a traditional automobile transporter, and federal statute bars any state length limit under 80 feet for a stinger-steered automobile transporter whose front overhang stays inside 4 feet and rear overhang inside 6 feet. States may allow longer.

Those are floors states must allow, not caps: state law can go longer, and loads that outgrow the legal envelope move on permits. Each state's legal width, height, and semitrailer length limits, plus its single-trip permit fee, live in oversize permit costs by state, and the full length-by-configuration table sits on each live state's oversize and overweight permits page. For scheduling the whole launch, the timeline in how long it takes to get authority holds for car haulers too.