Okla. Stat. tit. 68 § 2385.4
When an employer believes that he has made an overpayment of the tax required to be paid under Section 2385.3, he may file an application with the Tax Commission on a form approved by it either to have the amount of such overpayment refunded to him or to have the sum credited against the payment which he is required to make for a subsequent period, but such refund or credit shall be made or allowed to the employer only to the extent that the amount of such overpayment was not withheld under Section 2385.2 by the employer. Any employer aggrieved by the refusal of the Tax Commission to refund in accordance with an application duly filed by him may pursue the remedies provided in Article 2 of this Code, the Uniform Tax Procedure Law.
Okla. Stat. tit. 68, § 2385.4