When an original return has not been filed, the Commission will not issue a refund on an original income tax return filed 3 years after the original due date of the return. A refund that is "barred by statute" cannot be used as payment on any delinquent account or applied to estimated tax. Exceptions to the statute of limitations set out in 710:50-5-13 also apply to certain refund situations. [See: 68 O.S. § 2373 ]
Okla. Admin. Code § 710:50-9-2