---
title: "MC number"
url: https://carrierkyc.com/glossary/mc-number
description: "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."
---

# MC 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.

Also called: Motor carrier number, MC docket number, MC authority number. Category: FMCSA & freight.

FMCSA registers for-hire carriers of regulated commodities, freight forwarders and property brokers, and each authority carries a [docket number](https://carrierkyc.com/glossary/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](https://carrierkyc.com/guides/is-the-mc-number-going-away) covers what is and isn't changing.

> **Red flag: Red flags** An MC on a rate con or NOA that maps to a different USDOT or legal name. A claim that an MC is years old when the authority history shows a recent grant or reinstatement.

## Related

- [Is the MC number going away? What's actually changing](https://carrierkyc.com/guides/is-the-mc-number-going-away)
- [Docket number](https://carrierkyc.com/glossary/docket-number)
- [USDOT number](https://carrierkyc.com/glossary/usdot-number)
- [Operating authority](https://carrierkyc.com/glossary/operating-authority)
- [Carrier risk check](https://carrierkyc.com/tools/carrier-check)

## Sources

- [Federal Register: Availability of Motus, FMCSA's New Registration System](https://www.federalregister.gov/documents/2026/04/29/2026-08334/availability-of-motus-fmcsas-new-registration-system) (FMCSA notice, 2026-04-29)
- [NGWA: FMCSA announces new online registration system, Motus](https://www.ngwa.org/detail/news/2026/08/27/fmcsa-announces-new-online-registration-system--motus) (Summary of FMCSA's Motus guidance, 2026-08-27)
- [H.R. 8267, SAFER Transport Act (introduced text)](https://www.govinfo.gov/content/pkg/BILLS-119hr8267ih/html/BILLS-119hr8267ih.htm) (GovInfo, introduced 2026-04-14)