Okla. Stat. tit. 68, § 68-1104: Due date of tax - Delinquency - Reports on leases

(a) The tax provided for in Section 1101 and Section 1102 of

this Code shall become due on the first day of each calendar month

on all petroleum oil, natural gas and/or casinghead gas, produced in

the State of Oklahoma during the preceding monthly period, and if

the tax is not paid on or before the last day of the month when the

same becomes due, such tax shall become delinquent.

(b) Every person, firm, association, or corporation responsible

for paying or remitting the petroleum excise tax levied by this

article on the production from any lease shall file with the Tax

Commission a monthly report on each lease, regardless of sales or

purchases of production from said lease during the period, at the

same time and in the same manner as is required for the reporting of

the gross production tax.