Cal. Ins. Code § 2074.8
Notwithstanding any of the other provisions of Sections 2071 and 6010, those paragraphs in Sections 2071 and 6010 captioned "Cancellation of policy" may, in any policy subject to Chapter 11 (commencing with Section 675) of Part 1 of Division 1, have that paragraph in the text of the policy stricken or changed by endorsement and the following paragraph substituted therefor:
"This policy shall be canceled at any time at the request of the insured, in which case this company shall, upon demand and surrender of the policy, refund the excess of paid premiums above the customary short rate for the expired time. This policy may be canceled by this company by written notice mailed or delivered to the named insured at the address shown in the policy, with or without tender of the excess of paid premiums above the pro rata premiums for the expired time, stating when, not less than 20 days after that mailing or delivery, cancellation shall be effective. Notice of cancellation shall state that the excess premiums, if not tendered, will be refunded on demand, and contain those matters that are required to comply with Chapter 11 (commencing with Section 675) of Part 1 of Division 1."
Ca. Ins. Code § 2074.8