Okla. Stat. tit. 68, § 68-1208: Purpose and disposition of revenue - When due

A. It is hereby declared to be the purpose of Section 1201 et

seq. of this title to provide for revenue for general governmental

functions of the State of Oklahoma.

B. All monies collected under Section 1201 et seq. of this

title shall be transmitted monthly to the State Treasurer of the

State of Oklahoma to be placed to the credit of the General Revenue

Fund of the state, to be paid out only pursuant to direct

appropriations of the Legislature.

C. Except as otherwise provided by subsection D of this

section, the tax levied by Section 1201 et seq. of this title shall

become due and payable on July 1 of each year or at the option of

the taxpayer upon the last day of the income tax year of the

taxpayer, and if not paid on or before the next ensuing September 15

for taxpayers electing to pay tax by July 1, or the date by which an

income tax return is required to be filed pursuant to the provisions

of subsection G of Section 2368 of this title or pursuant to the

provisions of Section 216 of this title, for taxpayers electing to

pay the tax at the time such income tax return is due, the penalties

hereinafter provided shall apply.

D. For those taxpayers that remitted the maximum amount of tax

pursuant to Section 1205 of this title for the preceding tax year,

the tax levied by Section 1201 et seq. of this title shall become

due and payable on May 1 of each year, and if not paid on or before

the ensuing June 1, the penalties hereinafter provided shall apply.