Box Truck Decals: Door Lettering for USDOT, MC and Unit Numbers

Box truck decals usually go on as a matching pair, one on each cab door, carrying your company name and USDOT number. Add an MC line if you haul for hire, a unit number if you run more than one truck, and a height decal if you want the clearance where the driver will see it. One line is enough only when the rest of the marking is already on the truck.

The standard box truck set

The federal marking rule, 49 CFR 390.21, asks a commercial motor vehicle covered by the federal safety rules to show the carrier's legal name or a single trade name, as listed on its FMCSA registration, plus its USDOT number preceded by the letters "USDOT". It goes on both sides, in letters that contrast sharply with the background and can be read from 50 feet in daylight while the truck is stopped.

On a box truck that usually means two matching decals on the cab doors. A typical stack reads:

• ACME HAULING
• DALLAS, TX
• USDOT 1234567
• MC 890123

The Custom USDOT Logo puts all four lines on one decal. Prices are per decal, so order two for both doors. The city line is your choice: FMCSA says the rule does not require it and does not prohibit it.

When to add an MC line

The MC number is operating authority, not part of the marking rule. FMCSA says no marking requirement exists for displaying it. In general, carriers that haul regulated cargo for others in interstate commerce need operating authority, and carriers that move only their own cargo do not.

So add an MC line if you hold the authority and want it readable on the truck. If you do not hold it, leave it off. Not sure whether your truck needs a USDOT number at all? Start with do box trucks need a DOT number.

When a single-line decal is enough

The rule asks for the name and number on both sides but does not say where on the side they go (49 CFR 390.21). If your name is already lettered on the box, a number-only decal on each door can finish the set: the USDOT decal for one line, or the USDOT + MC two-line for two.

Then stand 50 feet from the stopped truck and check that the name and the number are both easy to read. If you are unsure whether a split layout counts, ask FMCSA or your state agency.

Unit numbers for more than one truck

A unit number is your own identification, not a federal marking. A short "UNIT 12" in the same spot on every truck lets a dispatcher or dock supervisor name a truck from across the yard. The Trailer / Unit Number pair is sized for box trucks as well as trailers, and the unit number guide has more on numbering a fleet.

The Box Truck Height Decal

The new Box Truck Height Decal is a single line with your truck's height, for example "HEIGHT 11 FT 3 IN" (sample text only). Measure your own truck at its tallest point, including anything mounted on the roof, and type that figure. Put it somewhere you pass every time you climb in, such as the driver's door.

Sizes, colors and install

The 12, 18 and 24 inch options are decal widths, not legal sizes. How big do USDOT numbers need to be explains the 50-foot test. Cab doors have a window, a handle and body lines, so outline the decal in masking tape and pick the widest option that sits flat.

Choose a sticker background and lettering color with a big gap in lightness, such as black on white or yellow, or white on black. Installation is DIY: wash and dry the door, level the decal with tape, and follow how to install truck door decals. The rule in plain words is on USDOT number display rules. Want to see your lines on a truck door first? Try the door builder.