California Code, Insurance Code - INS § 11580.10

Any liability insurer issuing or renewing an automobile liability policy or a motor vehicle liability policy within the meaning of subdivision (a) of Section 16054 of the Vehicle Code shall provide written notice to the named insured of the policy identification number that may be used for verifying financial responsibility for purposes of Section 16028 of the Vehicle Code. This notice may be provided in a written binder, if any, or in the policy documents provided upon issuance or renewal of the policy.The insurer shall provide at least two copies of the notice to the insured and shall, upon request and payment of the reasonable cost thereof, provide additional copies.