If an entity has a DOT number and is engaged in interstate commerce, then that entity is generally required to register for UCR. (For more information about businesses subject to UCR, see the UCR Handbook. This policy from the Federal Motor Carrier Safety Administration (FMCSA) provides guidance on when a new U.S. Department of Transportation (USDOT) number is or is not required following motor carrier ownership, form of business or operational changes.