California Code, Corporations Code - CORP § 416

(a) Every holder of shares in a corporation shall be entitled to have a certificate signed in the name of the corporation by the chairperson or vice chairperson of the board or the president or a vice president and by the chief financial officer or an assistant treasurer or the secretary or any assistant secretary, certifying the number of shares and the class or series of shares owned by the shareholder. Any or all of the signatures on the certificate may be facsimile. In case any officer, transfer agent or registrar who has signed or whose facsimile signature has been placed upon a certificate has ceased to be such officer, transfer agent or registrar before such certificate is issued, it may be issued by the corporation with the same effect as if such person were an officer, transfer agent or registrar at the date of issue.

(b) Notwithstanding subdivision (a), a corporation may adopt a system of issuance, recordation and transfer of its shares by electronic or other means not involving any issuance of certificates, including provisions for notice to purchasers in substitution for the required statements on certificates under Sections 417, 418, and 1302, and as may be required by the commissioner in administering the Corporate Securities Law of 1968,  1 which system (1) has been approved by the United States Securities and Exchange Commission, (2) is authorized in any statute of the United States, or (3) is in accordance with Division 8 (commencing with Section 8101) of the Commercial Code. Any system so adopted shall not become effective as to issued and outstanding certificated securities until the certificates therefor have been surrendered to the corporation.