Okla. Admin. Code § 710:50-12-2
The following words and terms, when used in this Subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Debt" means past-due, legally enforceable State income tax obligation unless other indicated.
"Debtor" means a person who owes a state income tax obligation.
"IRS" means the Internal Revenue Service, a bureau of the U.S. Department of the Treasury.
"Past-due, legally enforceable State income tax obligation" means a debt which resulted from:
(A) A judgment rendered by a court of competent jurisdiction, which has determined an amount of State income tax to be due;
(B) A determination after an administrative hearing which has determined an amount of state income tax to be due and which is no longer subject to judicial review; or,
(C) A State income tax assessment (including a self-assessment) which has become final in accordance with State law but not collected, and which has not been delinquent for more than 10 years.
"Tax refund offset" means withholding or reducing a tax refund overpayment by an amount necessary to satisfy a debt owed by the payee(s).
"Tax refund payment" means any overpayment of Federal taxes to be refunded to the person making the overpayment after the IRS makes the appropriate credits for any liabilities for any Federal tax on the part of the person who made the overpayment.
Okla. Admin. Code § 710:50-12-2