California Code, Vehicle Code - VEH § 34640

(a) A motor carrier permit shall not be granted to any motor carrier of property until one of the following is filed with the department:

(b) The workers' compensation certified under paragraph (1) of subdivision (a) shall be effective until canceled. The insurer shall provide to the motor carrier of property and to the department a notice of cancellation not less than 30 days in advance of the effective date.

(c) If, after filing the statement described in paragraph (3) of subdivision (a), the carrier becomes subject to the workers' compensation laws of this state, the carrier shall promptly notify the department that the carrier is withdrawing its statement under paragraph (3) of subdivision (a), and shall simultaneously file the certificate described in either paragraph (1) or (2) of subdivision (a).

(d) Whenever the department determines or is notified that the certificate of workers' compensation insurance or certification to self-insure a motor carrier of property will lapse or be terminated, the department shall suspend the carrier's permit effective on the date of the lapse or termination, unless the motor carrier provides evidence of valid insurance coverage pursuant to subdivision (a).