Motor Vehicles bearing official Department of State license plates cannot be used for commercial endeavors except for the incidental permissible use for commercial activity as explained below.
Article 42 of the Vienna Convention on Diplomatic Relations prohibits practice in the receiving State of "any professional or commercial activity" for personal profit. The same holds true for career consular officers pursuant to Article 57 of the Vienna Convention on Consular Relations. In addition, commercial activity by a member of the Foreign Mission Community admitted to the United States as a principal alien on a diplomatic visa is in violation of the visa status of such individual and thus prohibited by the immigration laws of the United States. In the event this restriction is violated, such persons would not enjoy, in connection with civil actions related to the commercial activity or employment, any otherwise available immunity from the civil jurisdiction of the courts of the United States.
Exception for Dependents from some Foreign Missions:
A different situation exists with respect to dependents of the classes of persons specified above. As a general rule, these dependents enjoy no right under international law to be commercially employed in the host State. They are, in the first instance, prohibited by U.S. immigrations laws from such employment or commercial activity in the United States. U.S. law permits dependent employment (country-by-country) on the basis of reciprocity and in accordance with procedures prescribed by the Department of State and the Department of Homeland Security.
Dependent Employment Program:
Under the dependent employment program, the dependents of various states are permitted to engage in employment in the United States. All such employed dependents would, however, as a consequence of taking up such employment, lose their civil immunity in connection with such employment under international laws (Articles 21(1) (C) and 34 (D) of the Vienna Convention on Diplomatic Relations) and in some cases, as a consequence of express provisions in bilateral agreements.
Incidental Permissible Commercial Use of Motor Vehicles:
The issue of the permissible commercial use of Motor Vehicles bearing Department of State license plates arises in connection with the relatively small class of dependents identified in the preceding paragraph. Chiefs of diplomatic or consular missions may themselves decline to permit the dependents of their personnel to use official-plated vehicles for a public and recognizable commercial purpose. From the Department of State's view, use of a personal automobile bearing Department of State license plates is permissible if incidental to a dependent taking up employment under the reciprocity-based employment program. The drivers of such vehicles are susceptible to civil suit for damages that are found to be caused by acts related to the employ.