What is an MC number?

The short answer

An MC number is a docket number. FMCSA assigns it to an operating authority: the registration that lets a company haul regulated freight for customers across state lines, or arrange that transportation as a broker. The prefix shows the kind of docket: MC for motor carriers and brokers, FF for freight forwarders and MX for Mexico-domiciled carriers.

A USDOT number identifies the company; a docket identifies an authority the company holds. FMCSA links each docket to a USDOT number, but many carriers with a USDOT number have no MC number at all. To find the carrier behind an MC number, enter it as “MC 123456” in the DOT number lookup.

Who needs operating authority

Federal law requires motor carriers to register for operating authority before providing transportation subject to FMCSA’s interstate jurisdiction (49 U.S.C. 13902), and brokers and freight forwarders register too. In practice that means:

• for-hire carriers hauling other people’s regulated freight across state lines;
• brokers that arrange that transportation for compensation;
• freight forwarders.

Operating authority is not required for private carriers hauling their own goods, for carriers that operate only within one state, or for carriers that haul only exempt commodities, such as ordinary livestock and unprocessed farm produce (49 U.S.C. 13506). Those carriers can still need a USDOT number.

How authority is granted

1. The company applies to FMCSA for operating authority, and the application receives a docket number.
2. The application is published in the FMCSA Register; anyone may protest it within 10 days (49 CFR 365.115).
3. The carrier’s insurer files proof of the required liability coverage with FMCSA, on Form BMC-91 or BMC-91X (49 CFR 387.311).
4. The carrier designates process agents for the states where it is authorized to operate, on Form BOC-3.
5. When the protest period has passed and the filings are on record, the authority becomes active.

Federal minimum liability coverage for for-hire carriers of non-hazardous property in interstate commerce, in vehicles of 10,001 pounds or more, is $750,000. It rises to $1,000,000 for oil and many hazardous materials, and to $5,000,000 for certain hazardous materials in bulk (49 CFR 387.9).

MC number vs. USDOT number

Authority data since May 2026

FMCSA now publishes operating-authority records from its Motus registration system. The legacy authority datasets on data.transportation.gov were last refreshed on May 14, 2026; the Motus Carrier dataset that replaces them notes that Motus assigns a unique docket number to each operating authority, while the legacy system allowed several authorities under one docket. Our pipeline reads the Motus datasets every day. Whether MC numbers will be retired altogether is a separate question: see FMCSA Motus: are MC numbers going away?

MC numbers in our files

mc_number holds the carrier’s MC docket, active or not, and active_dockets lists every docket whose authority is active, whatever its prefix. A carrier with at least one active docket is labelled for_hire_authorized in authority_class. Carriers registered as for-hire without an active docket are labelled for_hire_no_active_authority; most of them are intrastate carriers, which need no federal authority.

Authority follows registration. Of the 10,205 carriers that registered a USDOT number in the 30 days before the current snapshot, 5.4% hold an MC docket so far. That is why fresh leads label new registrations and authority grants as separate events.

More in glossary

• What is a USDOT number?
• The MCS-150 and the biennial update.
• Interstate vs. intrastate trucking.
• For-hire vs. private carriers.