The short answer
A USDOT number identifies your company to FMCSA for safety monitoring; it's required for most interstate commercial vehicles and some intrastate ones. An MC number is operating authority to haul regulated freight for hire across state lines. Many for-hire carriers need both. You apply for both through FMCSA's Unified Registration System, and you must update your USDOT information every two years with the MCS-150.
"Do I need an MC number or a DOT number?" is one of the most common questions new truckers ask. They're related but different. This guide explains MC number vs. DOT number: what each does, who needs which and how to apply.
What a USDOT number is
A USDOT number is a unique identifier FMCSA uses to track a company's safety information: inspections, crashes, audits and compliance reviews. Generally, you need one if you operate a commercial motor vehicle in interstate commerce that:
- Has a gross vehicle weight rating or gross combination weight rating of 10,001 lbs or more, or
- Transports 9 to 15 passengers (including the driver) for compensation, or 16 or more passengers, or
- Transports hazardous materials in quantities requiring placards
Some states also require USDOT numbers for intrastate carriers.
What an MC number is
An MC (motor carrier) number is a docket number for operating authority: permission to transport regulated commodities for hire in interstate commerce. You need it if you haul other people's freight across state lines for pay. Brokers and freight forwarders need authority too.
Side by side
| USDOT number | MC number | |
|---|---|---|
| Purpose | Safety identification and monitoring | Operating authority for for-hire interstate work |
| Who needs it | Most interstate CMVs; some intrastate | For-hire interstate carriers, brokers, freight forwarders |
| Insurance filing required | No federal filing by itself | Yes: BMC-91X and BOC-3 |
| Ongoing requirement | MCS-150 update every two years | Maintain insurance and process agent filings |
Which do I need?
| Situation | USDOT | MC |
|---|---|---|
| Hauling your own goods across state lines (private carrier) | Yes | Usually no |
| Hauling for hire across state lines | Yes | Yes |
| Hauling for hire within one state only | Depends on state | Usually no |
| Leased on to a carrier | You haul under the carrier's numbers | No |
| Freight broker | Not usually | Yes (broker authority) |
How to apply
Both are applied for through FMCSA's Unified Registration System (URS). New applicants receive a USDOT number, and if they apply for authority, an MC number. After your application is published, there's a protest period and you'll need insurance and BOC-3 filings on record before authority is active. Full steps: new authority truck insurance.
From application to your first load
The order filings usually happen in
- Step 1Get a USDOT number and apply for MC authority (FMCSA registration)
- Step 2FMCSA publishes the application; a protest period follows
- Step 3Insurer files BMC-91X; process agent files BOC-3
- Step 4Authority goes active once filings are on record
- Step 5UCR, IFTA and IRP as needed; book loads
The MCS-150 biennial update
Every carrier with a USDOT number must update its registration information (Form MCS-150) every two years, even if nothing changed. The filing month is based on the second-to-last digit of your USDOT number, and whether you file in odd or even years depends on the last digit. Missing it can lead to deactivation of your USDOT number and penalties.
What about the future of MC numbers?
FMCSA has announced plans to move toward using the USDOT number as the single identifier. Check FMCSA's current guidance before relying on any change.
Other registrations you'll need
- UCR, every year
- IFTA, if your qualified vehicle runs in two or more jurisdictions
- IRP apportioned plates, for interstate vehicles over the threshold
- State permits where required (for example, certain weight-distance taxes)
Questions truckers ask
What's the difference between an MC number and a DOT number?
A USDOT number identifies your company for safety monitoring. An MC number is operating authority to haul regulated freight for hire across state lines.
Do I need both an MC and a DOT number?
If you haul for hire across state lines, generally yes. Private carriers usually need only a USDOT number.
How often do I update my USDOT number?
Every two years with the MCS-150, based on the last two digits of your USDOT number.
Do leased-on drivers need their own MC number?
No. They run under the carrier's USDOT and MC numbers.
Written by the FairlyCover Editorial Team. This guide explains how coverage generally works. It isn't legal or insurance advice, and your policy wording always decides what's covered. How we write and review content.
