Cal. Ins. Code § 658
Where any admitted insurer, licensed to issue motor vehicle liability policies as defined in Section 16450 of the Vehicle Code, refuses to accept an applicant for a good driver discount policy as defined in paragraph (1) of subdivision (b) of Section 1861.02 or refuses to issue a good driver discount policy when written application has been made, and where the applicant meets the criteria for purchase of a good driver discount policy, the refusing insurer shall furnish the applicant for insurance a written statement within 10 days of the refusal explaining the reason or reasons relied upon for denying insurance coverage. Notwithstanding Section 1633.3 of the Civil Code, the written statement explaining the reason or reasons for denying the coverage may not be electronically delivered to the applicant unless the application for the good driver discount was electronically delivered to the insurer.
Ca. Ins. Code § 658