Commercial vehicle marking requirements: two items, both sides
Federal rules ask for very little on the side of a truck: the carrier's name and its USDOT number. Most marking problems start with leases, rentals, and name changes, when the truck and the registration stop matching.
Written by Inely Baez
The marking rule in numbers
Under the commercial vehicle marking requirements in 49 CFR 390.21T, every self-propelled commercial motor vehicle in interstate commerce must show the operating carrier's legal or single trade name and its USDOT number on both sides, in sharply contrasting letters readable from 50 feet in daylight.
Vehicle marking is one of the smallest compliance items on a truck, and one of the few an officer can check from across a parking lot. The core rule is short.
I lead operations at Simplex, and I treat marking as part of a process rather than a paint job. The name on the door has to follow every lease, rental, sale, and name change, or it stops matching the registration.
The full briefing, read aloud
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Generated with AI text-to-speech from this article's key insights, in order, rather than reading it word for word. Chapter times come from a transcript of the audio. The article itself was written and reviewed by Inely Baez.
Key takeaways
Two items, both sides
The operating carrier's legal name or single trade name, as on its MCS-150, and its number preceded by "USDOT".
Legibility, not letter size
Letters must contrast sharply and be readable from 50 feet in daylight while the truck is parked. The federal rule sets no minimum height.
Paint or removable signs both work
A removable device, such as a magnetic sign, is allowed if it meets the same standard and stays legible.
No MC number is required
The rule asks only for the USDOT number. As of September 2026, FMCSA has not eliminated MC numbers.
The operating carrier goes on the door
A leased truck shows the carrier running it. Rentals of 30 days or less may use the lessor's marking if the rental agreement rides along.
In this articleContents
What are the commercial vehicle marking requirements?
The commercial vehicle marking requirements call for two pieces of information on both sides of every self-propelled CMV. The rule in force is 49 CFR 390.21T; the version numbered 390.21 has been suspended indefinitely since 2017.
| Requirement | What the rule says |
|---|---|
| Name | The legal name or a single trade name of the carrier operating the vehicle, as listed on its Form MCS-150 |
| Number | The identification number FMCSA issued to the carrier, preceded by the letters "USDOT" |
| Location | Both sides of the vehicle |
| Contrast | Letters that contrast sharply in color with the background |
| Legibility | Readable in daylight from 50 feet while the vehicle is stationary, and kept that way |
| Method | Painted on, or a removable device that meets the same standard |
Other information, such as a logo or a unit number, may also appear, as long as it is not inconsistent with the required marking.
Is there a minimum letter size?
No. The federal rule sets no letter height and no font. The test is performance: can an officer read the name and number from 50 feet in daylight? Thin, decorative, or low-contrast lettering can fail that test at any size.Do you need your MC number on the truck?
No. The marking rule asks only for the USDOT number. When FMCSA adopted the current marking rule in 2000, it did not make carriers remove MC numbers, but encouraged them to stop displaying them on new or repainted trucks. As of September 2026, MC numbers still exist. FMCSA's April 29, 2026 notice on Motus, its new registration system, says Phase II will not eliminate MC and FF numbers, and that the new USDOT number suffixes are not required for marking CMVs. Our guide to FMCSA's Motus registration system covers the rollout.Which vehicles must be marked?
The federal rule covers every self-propelled commercial motor vehicle in interstate commerce, and the vehicles of intrastate carriers that need a hazardous materials safety permit. Trailers are not covered, except intermodal equipment, such as container chassis, which the intermodal equipment provider must identify.
What is a commercial motor vehicle?
Under 49 CFR 390.5T, a commercial motor vehicle is a vehicle used on a highway in interstate commerce to carry passengers or property when it:- Has a gross vehicle or combination weight rating, or actual weight, of 10,001 pounds or more, whichever is greater
- Is designed or used to carry more than 8 passengers, including the driver, for compensation
- Is designed or used to carry more than 15 passengers, including the driver, not for compensation
- Carries hazardous materials in a quantity that requires placards
How do you mark a leased or rented truck?
Mark it for the carrier operating it, not the one that owns it. The marking tells an officer who is responsible for the trip.
Owner-operators leased to a carrier
Under 49 CFR 376.11(c), the carrier leasing the truck must mark it under Part 390 for the length of the lease. It must also keep a copy of the lease, or a statement that it is operating the equipment, in the truck. If another name appears on the truck, such as the owner-operator's own business name, the carrier's name and USDOT number must follow the words "operated by." The lease must also say who removes the carrier's identification when the lease ends, under 49 CFR 376.12(e).Rentals of 30 days or less
A carrier renting a truck for 30 days or less can mark it as its own, or rely on the lessor's name and USDOT number. In the second case, the rental agreement must stay in the truck for the full term and show:- The renting carrier's name and the physical address of its principal place of business
- Its USDOT number, or instead whether it runs interstate or intrastate and whether it is hauling hazardous materials
- The lessor's statement that it cooperates with law enforcement to identify the customers who operate its rental vehicles
Driveaway moves
When the vehicle being driven is the shipment, a removable device with the carrier's name and USDOT number may go on both sides or on the rear. In a combination, it may go on both sides of any one unit or on the rear of the last unit.Do states have their own marking rules?
Yes, and they can reach vehicles the federal rule does not. California is a clear example, because its rules also cover intrastate trucks.
- Name on both sides. Vehicle Code section 27900 requires the operating carrier's name or trademark on both sides of for-hire vehicles, trucks with three or more axles, tractor-semitrailer combinations, and CMVs as California defines them. Section 27901 applies the same 50-foot daylight standard.
- The CA number. Under section 34507.5, carriers that need a California carrier identification number must display it on both sides. A vehicle that displays a valid USDOT number is exempt from that display.
- Old names come off. After a change of ownership or operation, old names and identifiers must be removed or covered within 60 days, and the vehicle re-marked before it runs on the highway again.
How to keep truck markings compliant
Each step ties the marking to the event that changes it.
Step 1: Match the name to your registration
The name on the door must be the legal name or single trade name on your MCS-150. Change the registration before the paint, and keep your MCS-150 biennial update current.Step 2: Mark every power unit before it runs
Check each new, replacement, and spare truck before it goes into service. Both sides, every time.Step 3: Read it from 50 feet
Stand 50 feet away in daylight and read the name and number. Judge contrast against the actual paint, not the design proof.Step 4: Put markings on the lease checklist
At onboarding, apply "operated by" where needed and place the lease or statement in the truck. At termination, the person the lease names removes the identification.Step 5: Recheck on a schedule
Magnets fall off, decals peel, and road film covers lettering. Add markings to your periodic inspection checklist, because the rule requires the marking to stay legible.
How Simplex helps you keep the door and the registration in step
The marking is only as good as the registration behind it. We help with both.
Registration that matches the door
Our authority packages cover your USDOT and MC applications, BOC-3, insurance filings, and MCS-150 setup and updates.
DOT safety compliance
Our DOT safety compliance team helps carriers stay compliant with FMCSA rules, from driver files to audit guidance and support.
Running in California
Our California motor carrier permit team can handle your MCP and the registration it depends on.
Frequently asked questions
What is considered a commercial motor vehicle?+
What are the lettering requirements for a semi truck?+
Can I use magnetic signs for my USDOT number?+
Do trailers need a USDOT number?+
Do I need to display my MC number on my truck?+
Where this information comes from
The requirements below come from federal regulation, the Federal Register, and the California Vehicle Code, checked on September 24, 2026.
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1
eCFR — 49 CFR 390.21T
What the marking must show, where, how legible, and the rental and driveaway rules.
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2
eCFR — 49 CFR 390.5T
The definition of a commercial motor vehicle.
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3
eCFR — 49 CFR 390.19T
The MCS-150, the name used on it, and the duty to display the USDOT number.
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4
eCFR — 49 CFR 376.11
How a carrier identifies leased equipment, and the lease copy or statement in the truck.
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5
Federal Register — Availability of Motus (April 29, 2026)
MC numbers kept in Motus Phase II; USDOT suffixes not required for marking.
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6
Federal Register — CMV Marking final rule (2000)
Why the USDOT number replaced the MC number on the truck.
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7
California Vehicle Code — Section 27900
California's name display rule and the 60-day removal of old names.
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8
California Vehicle Code — Section 34507.5
When the CA number must be displayed, and the USDOT number exemption.
Written by
Inely Baez
Chief Operating Officer, Simplex Group
Chief Operating Officer at Simplex Group, with nearly eight years at the company leading operational strategy and execution across compliance, technology, logistics, and performance systems. She is a Certified Public Accountant with a background spanning operations and finance, including leadership roles within Simplex's Freight 4 U division and Velox Transport Solutions. Her work focuses on building scalable, disciplined systems that support long-term performance and growth.
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Keep the door and the registration matching
The marking rule takes a minute to read and a minute to check. It goes wrong when a lease starts, a rental ends, or a name changes and nobody updates the truck.
If you want help lining up your markings, registration, and lease paperwork, talk to our team.