California Code, Revenue and Taxation Code - RTC § 6452

(a) On or before the last day of the month following each quarterly period of three months, a return for the preceding quarterly period shall be filed with the board in the form as prescribed by the board, which may include, but not be limited to, electronic media.Returns shall be authenticated in a form or pursuant to methods as may be prescribed by the board.

(b) For purposes of the sales tax, a return shall be filed by every seller and also by every person who is liable for the sales tax under this part. For purposes of the use tax, a return shall be filed by every retailer engaged in business in this state and by every person purchasing tangible personal property, the storage, use, or other consumption of which is subject to the use tax, who has not paid the use tax due to a retailer required to collect the tax.

(c) Any retailer or other person who fails or refuses to furnish any return required to be made, or who fails or refuses to furnish a supplemental return or other data required by the board, is guilty of a misdemeanor punishable as provided in Section 7153.