Okla. Stat. tit. 21, § 351

Every person who, in making any statement, oral or written, which is required or authorized by law to be made as the basis of imposing any tax or assessment, or of an application to reduce any tax or assessment, willfully states any material matter which he knows to be false, is guilty, upon conviction, of a misdemeanor and shall be punished by imprisonment in the county jail for not more than one (1) year or by the imposition of a fine not to exceed Five Thousand Dollars ($5,000.00), or by both said fine and imprisonment.