The excise taxes levied in this chapter shall become due and payable on or before the twentieth day of the month succeeding the month in which the tax accrues. Each distributor shall file with the commission a monthly report setting forth the quantity of compressed gas received within this state, less any authorized exemptions; the quantity of compressed gas sold for use on the highways of this state; and any other information as may be reasonably necessary for the administration of this chapter. The distributor shall remit to the commission, with the monthly report, the full amount of the excise tax shown thereon to be due.

Reports and payments sent to the commission by mail must be postmarked by the due date in order to be considered timely filed, except when the due date falls on a weekend or holiday, in which case such reports and payments must be postmarked by the first working day following the due date in order to be considered timely filed.

An amount equal to One-fourth Cent (¼¢) per gallon on all compressed gas shown to be taxable for highway use may be deducted; provided, that the One-fourth Cent (¼¢) per gallon tax on such compressed gas has been paid or is covered by the bond of a distributor of compressed gas.

The monthly report of the distributor shall be prepared and filed with the commission on forms prescribed by the commission or the distributor may, with the approval of the commission, furnish the required information on machine-prepared schedules. Such monthly reports shall be signed by the distributor or his duly authorized agent and contain a declaration that the statements contained therein are true and are made under the penalty of perjury.

All persons storing compressed gases, excepting natural gas, in underground caverns or cavities in this state shall make monthly reports of withdrawals of such compressed gases from storage, on forms prescribed by the commission at the same time, in the same manner, and subject to the same terms, conditions and penalties as is otherwise provided for distributors of compressed gas. Sales and deliveries of compressed gases to nonpermitted distributors shall be listed and reported on such reports separately from sales and deliveries to permitted distributors.