Truck Number Decals for Fleets: Unit Numbers Done Right

Truck number decals give every vehicle in your fleet its own identifier, such as UNIT 114, so dispatch, drivers and mechanics can tell trucks apart at a glance. Unit numbers are a carrier's own practice, not something the federal marking rule asks for. That means the format is up to you, and a little planning before you order saves a lot of mix-ups later.

Why carriers number their trucks

Many carriers use unit numbers to keep maintenance logs, fuel and toll records, damage reports and yard checks tied to one specific truck. When a driver calls in, "unit 114" is quicker and clearer than a plate or a VIN.

None of that is a federal requirement. The marking rule, 49 CFR 390.21, asks for the carrier's name and USDOT number on both sides of the self-propelled vehicle. It does allow other identifying information, as long as it is not inconsistent with what is required. See our USDOT number display rules for the summary.

One practical point: keep the unit number visibly apart from the USDOT number, on its own decal, its own line or with the word UNIT in front. A bare "114" next to "USDOT 1234567" can be misread as extra digits.

Pick one format and keep it

A fleet that mixes formats is hard to search and hard to read. Decide once:

• Fixed length. Write 007 instead of 7 if you may pass 99 trucks, so lists sort cleanly and every decal is the same width.
• One style. Choose UNIT 114 or #114 or just 114, and use it everywhere.
• Optional prefix. If you run mixed equipment, a letter can show the type, such as T for tractors and B for box trucks.
• No look-alike letters. Avoid O next to 0 and I next to 1.
• No reuse. Retire a number with the truck. A reused number makes old records ambiguous.

Each text line in the builder takes up to 24 characters, which is plenty for a unit number with a label.

Which decal fits which vehicle

Single-line number decals

The Single Regulation Number decal puts one number on its own decal. It is made for a CA number, KYU, TXDOT, GVW or a VIN, and it works for a unit number too. It comes in 12, 18 or 24 inch width and is $12.99.

Trailer and box truck pairs

The Trailer / Unit Number Decal is a matched pair with a GVWR line, sized for trailers and box trucks. It is listed at $18.99 and comes in 12, 18 or 24 inch width. You can add the last eight characters of the VIN or another identifier in the builder notes. For the weight line, see our guide on GVWR and weight stickers.

VIN decal

The new VIN Decal, $12.99, carries the vehicle identification number for a truck or trailer. Some fleets add it so someone in the yard can match a unit to its paperwork without a lookup.

Trailer decal numbers

The federal marking rule applies to the self-propelled vehicle, and FMCSA's 2000 final rule did not extend it to trailers. So how you number and label trailers is your call. Our guide to DOT requirements for trailers covers what is and is not required.

Ordering for a whole fleet

Each different number is its own decal, so each gets its own line in the cart. On the product page or in the builder, type the number, choose width and colors, set the quantity to 2 for both sides and add it to the cart. Then repeat for the next unit.

The quantity box goes up to 50 per line. When several trucks carry identical lettering, such as your company name and USDOT number, one line with a larger quantity covers all of them. Numbers that differ per truck need separate lines.

Here is an example. Six trucks, one 12 inch single-line unit decal per side, is 12 decals at $12.99, or $155.88. That is over $99, so shipping is free. See truck lettering cost for how the price builds, and the truck door decal size guide for choosing a width.

How to avoid duplicate or missing numbers

1. Keep one master list. For each unit, record the unit number, the last eight characters of the VIN, the plate and the date you ordered decals.
2. Order from the list, not from memory. Tick off each unit as you add it to the cart, and count the decals: two per truck, plus any rear or trailer decals you want.
3. Read every line in the preview. We make each decal exactly as you enter it. Our refunds and returns page says the guarantee does not cover a wrongly typed number.
4. Check on delivery. Compare each decal with your list before it goes on a truck, and note which unit it belongs to.
5. Walk the lot afterward. Confirm every unit shows the right number on both sides.