California Code, Revenue and Taxation Code - RTC § 18621.5

(a) Any return, declaration, statement, or other document required to be made under this part that is filed using electronic technology shall be in a form as the Franchise Tax Board may prescribe and is not complete, and therefore not filed, unless an electronic filing declaration is signed by the taxpayer, in accordance with Section 18621 in the case of individuals, subdivision (a) of Section 18505 in the case of estates or trusts, corporations, or limited liability companies classified as corporations for California income tax purposes, subdivision (a) of Section 18633 in the case of a partnership, or Section 18633.5 in the case of limited liability companies classified as partnerships for California income tax purposes. The Franchise Tax Board may prescribe forms and instructions for requiring the electronic filing declaration to be retained by the preparer or taxpayer and may require the declaration to be furnished to the Franchise Tax Board upon request.

(b) Notwithstanding any other provision of law, any return, declaration, statement, or other document otherwise required to be signed that is filed in a traditional medium and captured using electronic imaging technology shall be deemed to be a valid original document upon reproduction to paper form by the Franchise Tax Board.

(c) Notwithstanding any other law, any return, declaration, statement, or other document otherwise required to be signed that is filed by the taxpayer using electronic technology in a form as required by the Franchise Tax Board shall be deemed to be a signed, valid original document, including upon reproduction to paper form by the Franchise Tax Board.

(d) “Electronic imaging technology” means a system of microphotography, optical disk, or reproduction by other technique that does not permit additions, deletions, or changes to the original document. The system may include, but is not limited to, any magnetic media or other machine readable form.

(e) “Traditional medium” means any return, declaration, statement, or other document required to be made pursuant to this article other than those made using electronic imaging technology.

(f) “Electronic technology” includes, but is not limited to, computer modem, magnetic media, optical disk, facsimile machine, or telephone.