The Federal Motor Carrier Safety Administration (FMCSA) is warning motor carriers not to sell, purchase, or lease USDOT or operating authority numbers outside legitimate corporate transactions, saying such activity can lead to the immediate revocation of registrations.

In a notice issued March 13, the agency said attempts to transfer a USDOT number or MC operating authority between unrelated parties violate federal rules and could trigger enforcement action, including inactivation of the USDOT number and cancellation of associated safety registrations.

USDOT numbers function as unique identifiers for motor carriers, brokers, freight forwarders, and other regulated entities. The number is tied permanently to the legal person or company to which it was issued and cannot be sold, rented, or leased to another operator.

If the agency determines that a number is being used by someone other than the assigned entity, FMCSA said it will deactivate the number and revoke associated registrations required for operating authority and safety compliance.

The rules differ slightly depending on business structure. For example, if a sole proprietor sells their business, the buyer must obtain a new USDOT number because the number remains permanently tied to the original individual. In contrast, if a corporation is sold and continues operating as the same legal entity, the USDOT number may remain with the company, provided FMCSA records are updated to reflect the change in ownership.

Operating authority, often referred to as an MC number, is required for certain for-hire interstate transportation services. While authority may sometimes transfer as part of legitimate corporate transactions, FMCSA said carriers must follow proper reporting procedures and update company records to remain compliant.

The agency said it issued the reminder after discovering attempts to buy, sell, or lease USDOT and MC numbers through unofficial channels.

FMCSA said carriers involved in such transactions risk losing their operating authority and other registrations required to conduct interstate trucking operations.