California Code, Revenue and Taxation Code - RTC § 45151

(a) The fee imposed pursuant to Section 48000 of the Public Resources Code is due and payable to the board quarterly on or before the 25th day of the calendar month following the quarterly period for which the fee is due.  Each feepayer shall prepare a return in the form as prescribed by the board, which may include, but not be limited to, electronic media, showing the total amount of solid waste subject to the fee, the amount of fee for the period covered by the return, and any other information that the board determines to be necessary.  Returns shall be authenticated in a form or pursuant to methods as may be prescribed by the board.

(b) The feepayer shall deliver the return, together with a remittance of the amount of fee due, to the office of the board on or before the 25th day of the calendar month following the quarterly period for which the fee is due.