USDOT number versus MC number

USDOT is the census identity

Every motor carrier that meets the federal commercial-motor-vehicle thresholds must obtain a USDOT number and update a biennial census filing under 49 CFR 390.19. The number is painted on the truck, stored in crash reports, and used as the primary key in QCMobile. If you have only one identifier, get the USDOT number.

Private carriers (a manufacturer hauling its own goods, a utility, a construction company with dump trucks) often have a USDOT number and no MC number. They are still in the federal file. A name-only Google result that says "no MC number, so not a real trucking company" is wrong.

MC is operating authority for for-hire interstate work

An MC, MX, or FF docket is issued when a company obtains operating authority to haul for-hire in interstate commerce, or to broker that freight. Authority can be active, pending, or not authorized. The authority block in the lookup reports that status. A company can have a USDOT number and inactive authority. A company can have both broker and carrier dockets.

The door of the truck is required to show the USDOT number, not the MC number. If you only photographed an MC number from a website or a bill of lading, the lookup still accepts it and resolves it to a USDOT number.

Use either number; confirm the name

Enter the USDOT number, the MC number, or the legal name. Then confirm that the legal name and address match the crash report or the door photo. Affiliated companies sometimes share a trade name and have different USDOT numbers. The record you want is the one that matches the power unit that was in the crash.