Magnetic Truck Door Signs: What the Federal Rule Allows

Magnetic truck door signs are allowed under the federal marking rule, as long as the removable sign does everything a painted or decal marking has to do. It must appear on both sides, contrast sharply with the background, stay readable from 50 feet in daylight and be kept in that condition. The rule judges the result, not the material. Whether a magnet is a smart choice for your truck is a separate, practical question, and this guide covers both.

What the federal rule says about removable signs

The marking rule, 49 CFR 390.21, says the marking may be painted on the vehicle or may be a removable device. A removable device has to satisfy the same tests as paint:

• It appears on both sides of the self-propelled vehicle.
• The letters contrast sharply in color with the background they sit on.
• They are readable in daylight from 50 feet while the vehicle is stationary.
• The marking is kept and maintained so it stays that readable.

When FMCSA announced the rule, its news release said the provisions on removable marking devices, such as magnetic name tags, were retained. The rule also has a separate paragraph for driveaway and towaway moves that allows a removable device on both sides or at the rear of a single driven vehicle.

For the full plain-English summary, see our USDOT number display rules page. Rules change, so confirm your own requirements with FMCSA and your state.

Personal pickups and temporary signs

In its 2000 final rule, FMCSA answered a question about pickups. It said carriers who use their personal pickups for business can put on temporary signs and take them off when necessary.

That helps if you drive one pickup for both family and work. Whether your pickup needs a USDOT number at all depends on its weight, how it is used and whether it crosses state lines for business. Start with our guide on whether pickup trucks need DOT numbers.

Where a magnet works well

Magnets make sense when the sign really does need to come off:

• A shared or borrowed truck that carries different names at different times.
• A personal pickup that does business work only some days.
• A short job where lettering would be removed within weeks.

In each case the sign still has to be on, on both sides, whenever the truck is working as a marked vehicle. A magnet sitting in the cab does nothing.

Where a magnet causes trouble

Magnets are simple in theory and fussy in daily use.

• Only steel holds a magnet. Aluminum, fiberglass and plastic panels do not. Hold a small magnet to the door before you buy anything.
• The surface must be flat and clean. A curved panel, a ribbed door or a spot near a seam can let an edge lift, and wind can catch a lifted edge on the highway.
• Grit gets trapped. Dirt and water under a magnet can dull or scratch paint, so remove the sign and wipe both surfaces from time to time.
• They can be lost or stolen. A magnet that flies off, or gets taken, leaves that side of the truck with no marking.
• Someone has to remember. Every trip starts with checking both doors.

Store magnets flat, not bent around a corner, so they keep their shape.

Work Decals sells decals, not magnets

To be plain about it: we make adhesive vinyl decals to order, not magnets. If a magnet is what you need, you will have to buy it elsewhere.

An adhesive decal is usually the simpler choice when the truck stays with one carrier name, when the door is aluminum or fiberglass, or when you want the marking on every trip without thinking about it. A single USDOT Decal Sticker is $12.99 per decal, so a pair for both doors is $25.98 before shipping. Our 3-year guarantee replaces a decal that peels or comes off.

The trade-off is that a decal is not made to be moved. Our refunds and returns page says the guarantee does not cover damage from removal and reapplication. If you might swap the sign between trucks, a magnet fits better. If you ever need to take a decal off, read how to remove truck decals.

A quick way to decide

Ask yourself four things:

1. Is the door steel? Test it with a magnet.
2. Does this truck always run under the same name and USDOT number?
3. Will the sign ever need to move to another vehicle?
4. Will you reliably check both doors before every trip?

Steel, same name and a sign that never moves points to a decal. A shared truck or a part-time pickup points to magnets. Either way, the test at the roadside is the same: can your name and number be read from 50 feet away?

If you go with decals, the door builder shows your lettering on a truck door before you order, and our guide on how big USDOT numbers need to be explains the 50-foot test. For what each line costs, see truck lettering cost.