Glossary
USDOT number
A USDOT number is the registration number the Federal Motor Carrier Safety Administration (FMCSA) assigns to every company that operates commercial vehicles in interstate commerce. It identifies the company itself, not a license to haul: a carrier can hold a USDOT number and still lack the operating authority to move freight for hire.
What it tells you
The USDOT number is the thread that ties the whole federal record together. Inspections, crashes, safety ratings, insurance filings, and authority history all key off it. When you vet a carrier, the USDOT number is the identifier worth anchoring on; names change, dispatch emails change, but the USDOT record carries the company's history.
Active vs inactive
A USDOT record can go inactive when a company ceases operations, fails to update its registration, or is placed out of service. An inactive USDOT record on a company quoting you freight is a serious mismatch between paperwork and behavior; fleetfax surfaces it as a blocking issue.
USDOT vs MC
The USDOT number identifies the company; the MC number (docket number) historically identified its grant of operating authority. FMCSA has been consolidating registration around the USDOT number, so treat USDOT as the canonical identifier and the MC number as a legacy lookup that resolves to it. fleetfax accepts either and resolves MC to USDOT for you.
Related terms
MC number
The legacy docket number tied to a carrier's operating authority. Resolves to a USDOT number; still the number most load boards display.
Operating authority
FMCSA's grant of legal permission to operate for hire: common, contract, or broker. Active, inactive, pending, revoked, and the gaps in between.
MCS-150 (biennial update)
The registration form every carrier must refile at least every two years: fleet size, mileage, contact details. The freshness stamp on the federal record.
fleetfax reads public FMCSA data and is not affiliated with FMCSA or the U.S. Department of Transportation. This page explains terminology; it is not legal advice.