USDOT Number Example: Correct Door Lettering and Common Mistakes

A correct USDOT number example is short: the carrier's name on one line, then the letters USDOT and the number on the next, in letters that contrast sharply with the door. It appears on both sides, and it can be read from 50 feet in daylight with the truck stopped (49 CFR 390.21). The names and numbers below are made up. Yours come from your own FMCSA registration.

What a USDOT number looks like on a truck door

The number on the door is the identification number FMCSA issued to the carrier, preceded by the letters "USDOT." The name beside it is the legal name or a single trade name, as listed on the carrier's registration. That is the whole required marking. FMCSA's plain-language summary lists the same pieces (Motor Carrier Safety Planner).

Examples of correct lettering

Each line below is a separate line of lettering, shown with slashes.

• Name and number: ACME TRUCKING / USDOT 1234567
• With an MC number: ACME TRUCKING / USDOT 1234567 / MC 7654321. The MC line is allowed but not required. FMCSA says no marking requirement exists for it (FMCSA).
• With a city: ACME TRUCKING / TULSA, OK / USDOT 1234567. FMCSA said the rule does not require a city and state and does not prohibit them either (FMCSA).
• On a leased truck: J SMITH HAULING / OPERATED BY / ACME TRUCKING / USDOT 1234567. When another name is on the truck, the operating carrier follows it. Our operated by guide covers leases.
• On a pickup with removable signs: the same name and number, on a sign for each door. Removable markings are allowed if they pass the same tests (49 CFR 390.21).

Anything extra, such as a phone number or website, is allowed if it is not inconsistent with the required lines. Keep those smaller than the name and the USDOT line.

Common mistakes, and the fix for each

1. Leaving out the USDOT letters

A bare string of digits, or "DOT 1234567," does not match the wording. The rule asks for the number preceded by the letters "USDOT." Fix: put USDOT in front, on the same line as the number.

2. A name that does not match the registration

The name must be as listed on Form MCS-150, and FMCSA's summary of the rule says it must match that information (FMCSA). A nickname, a logo name or a dropped "LLC" can all drift from the record. Fix: look yours up free on SAFER and copy it letter for letter. See putting your company name on a truck.

3. Low contrast

Gray on white, dark blue on black and red on a dark door all fade out. The rule says the letters must contrast sharply with the background. Fix: pair light with dark. Our fonts and colors guide lists which pairings read clearly.

4. Too small or too fussy

The rule sets no height in inches, so there is no figure to measure against. The test is 50 feet in daylight. Script fonts, thin strokes and five crowded lines fail it first. Fix: stand 50 feet away and read it, using the steps in how big USDOT numbers need to be.

5. Only one side

The marking must appear on both sides of the vehicle. A decal on the driver door alone leaves the other side unmarked. Fix: order two decals, since each is priced per decal.

6. No operated by line on a leased truck

If another name is on the truck, the operating carrier's name and USDOT number must follow it, preceded by "operated by." A leased truck with only the owner's name on it is the usual miss. Fix: add the carrier's lines, as in the example above.

7. Marking the trailer instead of the truck

The marking rule applies to the self-propelled vehicle, not to towed trailers (Federal Register). A number on the trailer alone leaves the tractor bare. Fix: mark the power unit first. Trailer numbers are a separate question, covered in DOT requirements for trailers.

8. Using the MC number in place of the USDOT number

The MC number is operating authority. The USDOT number is the identifier the marking rule asks for. A door with MC alone is missing the required number. Fix: lead with the USDOT line and add MC below it if you want.

9. Dirty, cracked or peeling lettering

The rule says the marking must be kept legible. Road film, sun fade and a lifting corner can each fail the 50-foot test on a truck that was fine when new. Fix: look the decal over whenever you wash the truck, and replace one that has faded or cracked. A decal that peels or comes off is covered by our 3-year guarantee (refunds and returns).

Check your door

Stand at the side of the truck and answer yes or no:

• Does the name match my FMCSA record exactly?
• Does the number have the letters USDOT in front?
• Are the lines in contrasting colors, not close shades?
• Can someone read every digit from 50 feet in daylight?
• Is the marking on both sides, and on the truck itself?
• If another name is on the truck, do the words "operated by" and the carrier's lines follow it?
• Is it clean and flat, with no peeling edges?

Any "no" is worth fixing. Build your lines in the door builder to see them on a truck door first. The USDOT decal carries the number alone, the USDOT + MC two-line decal adds MC, and the Custom USDOT Logo adds the name and city. For where it goes on the door, see where to put the USDOT number on a truck. We make the decals. You are responsible for checking the rule, which can change, with FMCSA or your state.