41 CFR 102-34.95: -34.95 Government motor vehicle license plates.

U.S. Government license plates must be used on Government motor vehicles unless exempted under this subpart. U.S. Government license plates may not be used on motor vehicles not owned or leased by the Government. U.S. Government license plates for domestic fleets may be obtained from the U.S. Department of Justice, UNICOR (Federal Prison Industries). GSA has established a Memorandum of Understanding (MOU) on behalf of all Federal agencies with UNICOR for the procurement of official U.S. Government license plates. Each agency must execute an addendum to this MOU providing plate design and specific ordering and payment information before ordering license plates. U.S. Government license plate design will have numbers preceded by a letter code that designates the owning agency for the motor vehicle. For assistance with any issues involving license plates including to obtain a new license plate code designation, contact GSA at vehicle.policy@gsa.gov.