Truck Unit Number

What it is

Truck Unit Number decals are the internal fleet number — the digits (or letters and digits) that dispatch, the yard crew and the maintenance log use to identify one specific truck or trailer — cut from single-color vinyl at the height you specify. Send the list of numbers for your whole fleet in one order and every unit gets the same font, height and color, so the numbering looks consistent from truck to truck.

Where fleets place unit numbers

Unit numbers commonly go on the cab doors near the DOT number, on the rear doors, or high on the trailer nose where a yard spotter can read it from a distance while backing units into position. Placement is not federally regulated the way the USDOT number is — it is set by your own fleet's convention, so keep it consistent across units so drivers and yard staff always know where to look.

Sizes and pricing

Letter heights of 2, 3, 4 and 6 inches are available, with a character count from 1 to 6 (letters and digits both allowed, so "T-14" or "205" both work). The price is per sticker, so order one for every surface you mark.

Readability by letter height

Letter height	Rule-of-thumb readable distance
2 in	about 20 ft — cab doors, close inspection
3 in	about 30 ft — yard readability at a walk
4 in	about 40 ft — spotted from a moving forklift or yard truck
6 in	about 60 ft — read while backing a trailer into a dock

This is a rule of thumb for maximum impact, not a guarantee — pick the height based on how far away someone typically needs to identify the unit, such as a dispatcher scanning a yard.

Why it holds up

Cut from single-color vinyl in 13 standard colors rather than printed, unit numbers will not fade unevenly and are rated for 5+ years outdoors — important since these decals often stay on for the working life of the unit. Free transfer tape keeps multi-character numbers aligned during installation, and Reflective film is available if units need to be identified at night.

Who this is for

• Trucking and logistics fleets — consistent numbering across tractors and trailers for dispatch and maintenance tracking.
• Equipment rental yards — asset numbers on trailers, containers or heavy equipment.
• Municipal and utility fleets — unit numbers for service trucks tracked by a central dispatch.
• Growing fleets — adding new units and keeping the numbering scheme identical to existing trucks.

How to apply

A full fleet order can hold many numbers — keep the list you submitted handy so each sticker goes on the correct truck.

1. Wash the panel with soap and water, then wipe it with rubbing alcohol and let it dry completely — any wax, dust or grease under the vinyl will shorten how long it holds.
2. Work in a shaded spot between about 60 and 90 degrees F. Direct sun makes the adhesive grab too fast; cold makes it grab too slowly.
3. Peel back a corner of the backing paper and tack the decal in place to confirm the position before committing.
4. Use a strip of painter's tape as a hinge at the top so the decal stays aligned while you peel away the rest of the backing paper.
5. Squeegee from the center outward in overlapping passes to push air out toward the edges, not trap it in the middle.
6. If the order includes transfer tape, squeegee firmly over it, then peel the transfer tape back slowly at a low angle, checking that every letter released onto the surface.
7. Press down any edges or corners that did not fully bond, working from the center out.
8. If a small air bubble remains, prick it with a pin and press it flat — do not try to squeegee a large bubble out through the edge.
9. Give the adhesive time to cure — avoid washing the vehicle for at least 48 hours after installation.

Removal and care

Warm the film with a hair dryer or heat gun on a low setting, then peel it back slowly at a low angle rather than straight up — heat keeps the vinyl from tearing into small pieces. Any adhesive left behind comes off with an adhesive remover or rubbing alcohol, then a regular wash. Because it is rated for 5+ years outdoors, you can leave it on through winters and regular washing and remove it later without stripping paint, as long as the clear coat underneath is in normal condition. When a unit is retired, resold or renumbered, the decal comes off clean, so the panel is ready for a new number without a ghost outline of the old one.