MC Number (Motor Carrier Number)
A docket number assigned by FMCSA to for-hire carriers and brokers when they register for operating authority. Unlike DOT numbers (required for all interstate CMV operators), MC numbers are specific to for-hire and brokerage operations. CarrierOk supports lookup by MC number, DOT number, or legal name.
Definition
The MC number (Motor Carrier number) is a docket identifier assigned by FMCSA when a company applies for operating authority as a for-hire carrier, broker, or freight forwarder. The 'MC' prefix stands for Motor Carrier, though brokers receive the same format (sometimes referenced as MC-B for clarity, though the official prefix is the same). MC numbers are distinct from DOT numbers — a DOT number is required for any entity operating commercial vehicles in interstate commerce (including private carriers), while an MC number is required only for entities that need operating authority to transport regulated commodities for compensation or to arrange such transportation. A single company may hold both a DOT number and an MC number. In some cases, a company may hold multiple MC numbers if it has both carrier and broker authority. The MC number is the identifier used on the operating authority grant document and is referenced in insurance filings (Form BMC-91 for BIPD). CarrierOk indexes both DOT and MC (docket) numbers, and the API accepts either for carrier lookup. The docket_number and docket_prefix fields in the API response contain the MC number components.
Why It Matters
For Underwriters
MC numbers identify the specific authority grant — a carrier may have multiple dockets if they hold both carrier and broker authority, and each represents a distinct risk exposure.
For Brokers
Collecting the MC number at onboarding lets you verify the carrier's authority type and confirm they're authorized for the specific operations you need (for-hire hauling vs. brokerage).
For Developers
The CarrierOk API accepts both dot_number and docket_number for lookups — support both in your UI to accommodate users who may have one but not the other.
In the API
/v2/profileRelated Fields
docket_numberdocket_prefixdot_numberlegal_nameauthority_commonauthority_brokerFrequently Asked Questions
What is an MC number in trucking?
An MC number is a docket identifier assigned by FMCSA when a company registers for operating authority as a for-hire carrier, broker, or freight forwarder. It identifies the specific authority grant and is referenced on the authority document and insurance filings. Not all carriers have MC numbers — only those operating for-hire or as brokers need one. Private carriers operating only their own goods need just a DOT number.
Do I need both a DOT number and an MC number?
It depends on your operations. All interstate commercial vehicle operators need a DOT number. You additionally need an MC number if you transport regulated commodities for-hire (common or contract carrier) or if you arrange transportation as a broker or freight forwarder. Private carriers hauling only their own goods need a DOT number but not an MC number.
Related Terms
DOT Number (USDOT Number)
A unique identifier assigned by the U.S. Department of Transportation to every motor carrier, broker, and freight forwarder in interstate commerce. The DOT number is the primary key for looking up safety records, insurance, and authority in FMCSA databases. CarrierOk indexes over 4.2 million DOT numbers.
Operating Authority
FMCSA-granted permission for a motor carrier, broker, or freight forwarder to operate in interstate commerce. Authority types include common (general for-hire), contract (specific shippers), and broker. CarrierOk tracks authority status changes same-day and alerts subscribers when a carrier's authority lapses or is revoked.
BOC-3 (Blanket of Coverage)
A form filed with FMCSA designating process agents in every state where a motor carrier operates. Process agents accept legal documents on behalf of the carrier. A valid BOC-3 is required before FMCSA activates operating authority. CarrierOk includes BOC-3 agent details in carrier profiles.