Full explanation
A DOT (Department of Transportation) number is a unique identifier assigned to commercial vehicles and motor carriers by the Federal Motor Carrier Safety Administration (FMCSA). Every carrier operating commercial vehicles transporting passengers or hauling cargo in interstate commerce must register for a USDOT number. The number is used to monitor and track a carrier's safety information during audits, compliance reviews, crash investigations, and inspections. As of 2025, there are over 757,000 active for-hire carriers registered with DOT numbers in the United States. The DOT number must be displayed on both sides of each commercial motor vehicle operated by the carrier, along with the carrier's legal name or DBA name. Carriers can obtain a DOT number through the FMCSA's Unified Registration System (URS). The number remains assigned to the carrier permanently — even if the carrier goes inactive, the DOT number is not reassigned to another entity. This permanence makes DOT numbers valuable for tracking carrier history across name changes, address moves, and ownership transfers.
Source: FMCSA: USDOT Number Registration
Frequently asked questions
How do I find a carrier's DOT number?
You can look up any carrier's DOT number on Truck Graph using their company name, MC number, or physical location. The FMCSA SAFER system also provides DOT number lookups.
Is a DOT number the same as an MC number?
No. A DOT number identifies the carrier for safety monitoring purposes, while an MC (Motor Carrier) number is an operating authority permit. A carrier needs both to legally haul freight in interstate commerce.
Do all trucks need a DOT number?
Commercial motor vehicles operating in interstate commerce must have a DOT number if they transport passengers (9+ including driver) or haul cargo over 10,001 lbs GVWR, transport hazardous materials requiring placards, or operate for compensation across state lines.
Related terms
A Motor Carrier operating authority number issued by FMCSA that permits carriers...
FMCSA AuthorityOfficial permission from the Federal Motor Carrier Safety Administration to oper...
Operating AuthorityLegal permission to operate as a for-hire carrier, broker, or freight forwarder ...
New Entrant CarrierA motor carrier that has held FMCSA operating authority for less than 18 months ...