Glossary · FMCSA & freight
MC number
Also called: Motor carrier number, MC docket number, MC authority number
Definition
An MC number is the docket number FMCSA assigns to a for-hire motor carrier's or broker's interstate operating authority, separate from the company's USDOT number.
FMCSA registers for-hire carriers of regulated commodities, freight forwarders and property brokers, and each authority carries a docket number with a prefix; MC is the one most carriers and brokers hold. A USDOT number identifies the company, while the MC number identifies its authority to operate for hire.
MC numbers have not been eliminated. FMCSA left the elimination of MC and FF numbers out of the Motus Phase II release and said it would take a measured approach in later releases. The SAFER Transport Act (H.R. 8267), introduced on 2026-04-14, would phase MC numbers out over 5 years in favor of USDOT numbers, but it was referred to committee and is not law.
Motus randomizes newly issued docket numbers, so an MC number's size says nothing about its age. Search by USDOT or MC, but key your records on USDOT, and check that every MC on a document maps to the same company. The MC number guide covers what is and isn't changing.
Sources
- 01Federal Register: Availability of Motus, FMCSA's New Registration System · FMCSA notice, 2026-04-29
- 02NGWA: FMCSA announces new online registration system, Motus · Summary of FMCSA's Motus guidance, 2026-08-27
- 03H.R. 8267, SAFER Transport Act (introduced text) · GovInfo, introduced 2026-04-14