DOT Number Requirements Canada — Size, Placement & Rules 2026

Last updated: March 2026 | Source: FMCSA 49 CFR Part 390

What is a USDOT Number?

A USDOT (United States Department of Transportation) number is a unique identifier issued by the Federal Motor Carrier Safety Administration (FMCSA) to commercial vehicles that operate in interstate commerce in the United States. For Canadian truckers, this becomes relevant the moment you cross the border at Niagara Falls, Windsor, Sault Ste. Marie, or any of the 13 Canada-US crossings in Ontario.

Which Canadian Trucks Need a USDOT Number?

Canadian commercial motor vehicles crossing into the United States must obtain and display a USDOT number if the vehicle:

• Has a gross vehicle weight rating (GVWR) of 4,536 kg (10,001 lbs) or more
• Is designed or used to transport 9 or more passengers including the driver for compensation
• Transports hazardous materials in quantities requiring placarding

Purely domestic Ontario operators who never cross the US border do not need a USDOT number — they operate under their CVOR registration instead. However, the moment a vehicle enters the United States, FMCSA regulations apply.

DOT Number Size Requirements

FMCSA 49 CFR 390.21 specifies the marking requirements for commercial motor vehicles. The USDOT number must be:

• Minimum 2 inches (50mm) in height — same as Ontario's CVOR requirement
• In a colour that contrasts with the vehicle background
• Legible from a distance of 50 feet (approximately 15 metres) during daylight hours
• Displayed on both sides of the power unit (truck cab or tractor)

DOT Number Placement on the Vehicle

The DOT number must appear on both sides of the commercial motor vehicle. Specifically, FMCSA requires it on the power unit — the truck cab or tractor — not the trailer. Placement requirements:

• On the cab door or immediately adjacent area on both sides of the vehicle
• Must be accompanied by the company's legal name or trade name
• Must include the USDOT number with the prefix "USDOT" clearly indicated
• Must be kept clean and legible at all times

Combining CVOR and USDOT on the Same Decal

Many Ontario operators running cross-border routes combine their CVOR number and USDOT number on a single door decal for clean presentation and maximum compliance. Our Custom CVOR & USDOT Door Decals are designed exactly for this purpose — one professionally formatted decal that satisfies both Ontario MTO and US FMCSA requirements.

A typical combined decal displays:

• Company name (top line — largest text)
• City, Province (second line)
• CVOR: XXXXXXXX (third line — 50mm+ height)
• USDOT: XXXXXXX (fourth line — 50mm+ height)
• GVW: XX,XXX KG (fifth line, if applicable)

Fines for Missing DOT Numbers at the US Border

FMCSA violations for improper or missing commercial vehicle marking can result in out-of-service orders at the port of entry, plus civil penalties ranging from $1,691 to $19,933 per violation (2026 penalty schedule, adjusted for inflation). US border crossing officers have authority to hold commercial vehicles until compliance markings are confirmed. Don't let a missing decal cost you a border crossing delay and a five-figure fine.

How to Get a USDOT Number

Canadian carriers can register for a USDOT number through the FMCSA's online registration system at safer.fmcsa.dot.gov. Registration is free. Once your number is issued, you must display it on your commercial vehicle before crossing into the United States. Our compliance decals can be ordered and shipped to you before your first cross-border run.