California Code, Vehicle Code - VEH § 34685

(a) When the Department of the California Highway Patrol issues a carrier identification number pursuant to Section 34507.5 to a private carrier of passengers, it shall inform the carrier of the provisions of this division and the requirement that the carrier register with the department.

(b) The Department of the California Highway Patrol shall periodically, but not less frequently than quarterly, transmit to the department a list of the persons, firms, and corporations identified as private carriers of passengers to which it has issued a carrier identification number.  Upon receipt of the list, the department shall notify the private carriers of passengers of the registration requirements and of the penalties for failure to register.