The USDOT Number is a unique identifier that FMCSA uses to identify an employer or person’s operations. MAP-21 added a new requirement for safety registration for every employer or person operating commercial motor vehicles in interstate commerce. All distinct registrations or permits (e.g., operating authority registrations, safety registration, cargo tank facility registration, hazardous materials safety permits) held by one entity will eventually be associated with the USDOT Number. Safety registration is required for any employer or person operating commercial motor vehicles (CMVs) in interstate commerce. Safety registration is distinct from the USDOT Number. Before the Agency will issue safety registration, it must first determine that the applicant is willing and able to comply with all applicable statutory and regulatory requirements, is not affiliated with an unfit registrant or applicant, and has disclosed all relevant affiliations. In addition, MAP-21 requires every broker, freight forwarder, or motor carrier (whether operating commercial motor vehicles or not) to obtain a USDOT Number. FMCSA is modernizing its registration systems and process to eventually implement these MAP-21 requirements, however, safety registration will not be implemented with the first release of the new registration system.