Okla. Stat. tit. 68, § 68-2373: Claim for refund — Return required — Limitation period

A. Any claim for refund filed pursuant to this section must be

made on a return, in the form prescribed by the Oklahoma Tax

Commission.

B. Any claim for refund of an overpayment of any tax imposed by

Section 2355 of this title must be made within three (3) years from

the due date of the return, including the period of any extension of

time for filing a return, or two (2) years from the payment of the

tax liability, whichever of such periods expires later, or if no

return was filed by the taxpayer, within two (2) years from the time

the tax was paid.

C. Except as provided in subsection H of Section 2375 of this

title, no refund shall be allowed or made after the expiration of

the period of limitation prescribed in subsection B of this section

for the filing of a claim for refund, unless a claim for refund is

filed by the taxpayer within such period. If a claim for refund is

filed during the period prescribed in subsection B of this section,

the amount of the refund, if any, shall not exceed the amount of tax

paid within the period, immediately preceding the filing of the

claim, equal to three (3) years plus the period of any extension of

time for filing a return. If the claim was not filed within the

three (3) year period prescribed in subsection B of this section,

the refund shall not exceed the portion of the tax paid during the

two (2) years immediately preceding the filing of the claim.

D. If, upon any revision or adjustment, including overpayment

or illegal payment on account of income derived from tax-exempt

Indian land, any refund is found to be due any taxpayer, it shall be

paid out of the "Income Tax Withholding Refund Account", created by

Section 2385.16 of this title, in the same manner as refunds are

paid pursuant to such section.

E. The three-year limitation set forth in subsection C of this

section shall not apply to the amount of refunds payable upon claims

filed by members of federally recognized Indian tribes or the United

States on behalf of its Indian wards or former Indian wards, to

recover taxes illegally collected from tax-exempt lands. In the

case of any refund to a member of a federally recognized Indian

tribe or to the United States on behalf of its Indian wards or

former Indian wards, to recover taxes illegally collected on bonus

payments from oil and gas leases located on tax-exempt Indian lands

pursuant to this section, the Tax Commission shall pay interest on

all refunds issued after January 1, 1996, at the rate of six percent

(6%) per annum from the date of payment by the taxpayer to the date

of the refund.

F. In cases that the Tax Commission and the taxpayer have

signed a consent, as provided by law, extending the period during

which the tax may be assessed, the period during which the taxpayer

may file a claim for refund or during which an allowance for a

refund may be made shall be automatically extended to the final date

fixed by such consent plus thirty (30) days.

G. The Oklahoma Tax Commission may authorize the use of direct

deposit in lieu of refund checks for electronically filed income tax

returns.