Okla. Stat. tit. 68, § 223 (2026)

agreements - False or fraudulent or failure to file report or return. A. No assessment of any tax levied under the provisions of any state tax law except as provided in this section, shall be made after the expiration of three (3) years from the date the return was required to be filed or the date the return was filed, whichever period expires the later, and no proceedings by tax warrant or in court without the previous assessment for the collection of such tax shall be begun after the expiration of such period. No assessment shall be required if a report or return, signed by the taxpayer, was filed and the liability evidenced by the report or return has not been paid. If the assessment has been made within the limitation period set forth in this subsection, the tax may be collected by tax warrant or court proceeding, but only if the tax warrant is issued or the proceeding begun within ten (10) years after the assessment of the tax has become final. B. Where before the expiration of the time prescribed in subsection A of this section for the assessment of the tax, both the Tax Commission and the taxpayer have consented in writing to its assessment after such time, the tax may be assessed at any time prior to the expiration of the period agreed upon, and the period so agreed upon may be extended by subsequent agreements in writing made before the expiration of the period previously agreed upon. In those instances where the time to file a claim for a refund has not expired at the date the extension agreement is entered into, the entering into such an agreement shall automatically extend the period in which a refund may be allowed or a claim for a refund may be filed to the final date of such agreement. C. In the case of a false or fraudulent report or return, with intent to evade tax, the tax may be assessed, or a proceeding in

court for collection of such tax may be begun without assessment, at any time. The term “false or fraudulent” as used in this subsection shall have the same meaning as when used in Section 6501 of the Internal Revenue Code. D. In the case of a willful attempt in any manner to defeat or evade tax imposed by this title, the tax may be assessed, or a proceeding in court for the collection of such tax may be begun without assessment, at any time. E. In the case of a failure to file a report or return, the tax may be assessed, or a proceeding in court for the collection of such tax may be begun without assessment, at any time. Added by Laws 1965, c. 414, § 2, emerg. eff. July 7, 1965. Amended by Laws 1996, c. 34, § 1, emerg. eff. April 8, 1996; Laws 1999, c. 168, § 1, eff. Nov. 1, 1999; Laws 2006, c. 134, § 1, eff. July 1, 2006.