USDOT vs MC number: what each one is and who needs which
The USDOT number: your safety ID
FMCSA says companies subject to the federal safety rules must have a USDOT number. It identifies your company for safety records, audits, inspections and the CSA program. It is free to get and belongs to the same legal person for good. FMCSA says it can't be sold, rented or leased.
The MC number: permission to haul for hire
MC stands for motor carrier, and the MC number is your operating authority docket number. FMCSA describes operating authority as the registration that sets what type of operation you can run and what cargo you can carry. Freight forwarders get FF numbers and Mexico-based carriers MX numbers.
It comes with more strings: a $300 fee per authority type, insurance filed by your insurer, and a BOC-3 process agent filing. See How to get an MC number.
Who needs which
- USDOT only: private carriers hauling their own goods across state lines (a contractor hauling his own equipment, for example), for-hire carriers hauling only exempt commodities, and intrastate carriers in states that require a USDOT number.
- USDOT and MC: for-hire carriers moving regulated freight owned by someone else across state lines, carriers moving passengers across state lines for pay, and brokers and freight forwarders.
- Neither: operations that don't meet the federal or state thresholds. See Do I need a USDOT number?
Not sure? FMCSA's free USDOT Wizard sorts it out.
Changes coming
FMCSA has proposed dropping MC numbers so the USDOT number becomes the single identifier. It says that needs a future rulemaking and wasn't part of the first Motus release, and existing MC numbers won't be replaced. Meanwhile, companies registering for the first time in Motus see suffixes next to their USDOT number showing each registration type. FMCSA says suffixes are not a vehicle marking requirement.
Which one goes on the truck
Under 49 CFR 390.21T the door marking is your legal or single trade name plus your USDOT number with USDOT in front of it, on both sides. The MC number isn't part of that federal rule; see MC number on truck. Build the door set at USDOT truck lettering, from $59 for both doors.
Related questions
What does MC mean in trucking?
MC stands for motor carrier. The MC number is the docket number for your FMCSA operating authority, which lets you haul regulated freight for hire across state lines.
Do I need an MC number if I have a USDOT number?
Only if you are for-hire and cross state lines with regulated freight or passengers, or you are a broker or freight forwarder. Private carriers hauling their own cargo don't need one.
Does the MC number have to be on my truck?
The federal marking rule, 49 CFR 390.21T, requires your name and USDOT number, not the MC number.
- FMCSA: Getting started with registration
- Utah DOT: USDOT numbers and registering with the FMCSA
- FMCSA FAQ: What is operating authority (MC number) and who needs it?
- FMCSA: Types of operating authority
- FMCSA FAQ: What is the cost for obtaining operating authority?
- FMCSA: USDOT Wizard
- FMCSA: Do not sell, purchase, or lease a USDOT or MC number
- FMCSA: Registration modernization FAQs
- FMCSA: What's coming with Motus
- 49 CFR 390.21T, marking of self-propelled CMVs
- FMCSA, Do I need a USDOT number?
- FMCSA, How do I get operating authority (MC number)?
Checked against the current regulations September 2026. This is a plain-English summary, not legal advice. When your situation is unusual, ask the CHP, FMCSA or CSLB directly.