Skip to content

Frequently Asked Questions | DOTNumberStore.com

Frequently Asked Questions

Need help fast? Most questions are answered below. If you still need assistance, contact us and we’ll help you get it right.

Contact Us  |  Vinyl Installation Help


Quick Links


Compliance & DOT Requirements

Q: Do I legally need a USDOT number on my truck?
A: If your vehicle is used in interstate commerce and meets federal thresholds (typically over 10,001 lbs GVWR), FMCSA regulations require a visible USDOT number. Requirements vary by state for intrastate-only operations.

Q: What size must my USDOT lettering be?
A: FMCSA requires lettering to be clearly legible from 50 feet during daylight. While there is no exact size mandated, most compliant vehicles use lettering at least 2 inches high. Larger vehicles often use 2–3 inches for best visibility.

Q: What information must be displayed with my USDOT number?
A: Generally you must show your legal business name (or DBA), your USDOT number, and (in some cases) the city & state of business. Each operating authority and state may have additional requirements.

Q: Where should my USDOT markings be placed on the vehicle?
A: Typically on both sides of the power unit in a clear, unobstructed spot. They must remain visible at roadside inspection distance.

Q: What happens if my truck markings are not compliant?
A: Non-compliant markings can lead to roadside inspection violations, fines, or potential out-of-service orders depending on severity.

Q: Do DOT inspectors check vehicle lettering?
A: Yes. Legibility, accuracy, and visibility are common inspection points.

Q: Can faded or cracked decals cause violations?
A: Yes. Markings must remain legible. Damaged, peeling, or faded graphics can trigger inspection issues.


Magnets vs Decals (Which Should I Choose?)

Q: Vinyl decals vs magnetic signs — which is better?
A: Vinyl decals are sleek, permanent, and offer excellent longevity. Magnetic signs are removable, flexible, and reusable. Choose based on your fleet needs, vehicle materials, and how often your information changes.

Q: Can magnetic signs be used instead of permanent decals?
A: Yes. Magnetic signs are compliant when they are securely attached and clearly legible at the required distance, making them a flexible alternative to permanent decals.

Q: Are magnetic signs DOT compliant?
A: Yes — when they meet legibility and attachment requirements. Poorly sized or loose magnets can result in violations.

Q: Can magnetic signs fly off at highway speeds?
A: Correctly sized, thick magnetic signs applied flat to steel surfaces are designed to hold at highway speeds. Curved panels, body seams, or thin magnets increase risk.

Q: What thickness magnetic signs work best for vehicles?
A: Thicker magnets generally provide stronger hold and better durability, especially for highway use.

Conversion tip: If you’re unsure whether magnets will work on your vehicle, see the compatibility section below (a quick fridge-magnet test).


Surface Prep & Installation

Q: Does the surface need preparation prior to applying vinyl graphics or magnets?
A: Yes. Clean the surface of dirt, dust, grease, and moisture before application. This ensures proper adhesion for vinyl decals, and for magnets it ensures a stronger bond with steel surfaces.

Q: What is the best way to apply the vinyl graphic?
A: Visit our installation page for step-by-step instructions and a video guide. Proper alignment and surface preparation helps ensure longevity.

Q: Can decals be repositioned after application?
A: Most vinyl decals are permanent adhesive and not designed for repositioning. Magnetic signs are ideal when repositioning is needed.


Care, Cleaning & Lifespan

Q: After the magnetic sign or vinyl decal is applied, does it require any maintenance?
A: Vinyl decals are virtually maintenance-free once applied. Clean your vehicle normally, but avoid direct high-pressure washing on the graphic. Magnets should be removed regularly and the surface underneath cleaned to prevent dirt and moisture buildup.

Q: How long should I expect my US DOT stickers to last?
A: Our vinyl stickers are rated for outdoor use and often last 3–7 years in typical conditions. Magnetic signs generally last 3–5 years with proper care.

Q: How long do vinyl USDOT decals last?
A: High-quality outdoor vinyl decals typically last 5–7 years depending on weather exposure, UV conditions, and vehicle maintenance.

Q: How long do magnetic signs last?
A: With good care and cleaning, high-quality magnetic signs can last multiple years (often 3–5 years) before fading or losing strength.

Q: Will decals damage my vehicle paint?
A: Properly applied vinyl decals generally do not harm factory paint. Damage typically occurs when surfaces are dirty, low-quality adhesive is used, or removal is done incorrectly.

Q: Do magnetic signs damage paint?
A: Not when used correctly. Damage typically results from dirt trapped beneath magnets or leaving magnets on wet surfaces for extended periods. Remove and clean regularly.


Vehicle Compatibility

Q: Do US DOT number magnets stick to all vehicles?
A: No. Magnets stick only to steel surfaces. If your vehicle has aluminum or fiberglass doors (common on many newer vehicles), choose decals instead. Test with a refrigerator magnet — if it sticks, our magnets will too.


Shipping & Delivery

Q: How long does it take to receive my order?
A: With free shipping, expect delivery within about 7–10 business days. Shipping upgrade options and carriers are shown at checkout — delivery times vary by method.

Q: What are the shipping options and upgrades available, and how do they differ?
A: We offer USPS and UPS options like Priority Mail and Next Day Air. Each carrier and option has different delivery estimates, and details are displayed at checkout.

Q: Is Next Day Air shipping available for Saturday delivery?
A: No. Next Day Air orders placed before cutoff on Thursday ship Friday and typically deliver Monday. Saturday delivery is not offered.


Guarantee & Quality

Q: Does your product come with a guarantee?
A: Stickers are protected against manufacturing defects for up to 90 days. Magnetic signs are warranted against fading, peeling, and cracking for 1 year.


Website / Cart Issues

Q: When I add something to my cart and go to checkout, why is there nothing in my cart?
A: Most likely you are using an outdated browser. Our site performs best on modern browsers like Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge, or Opera.


Still not sure what you need?

If you want help choosing magnets vs decals (or checking your vehicle material), reach out and we’ll point you in the right direction.

Contact Us