Mississippi Code Title 27. Taxation and Finance § 27-7-317

(1) Any employer who makes an overpayment of the tax required to be remitted to the commissioner by Section 27-7-309 may file application with the commissioner, on a form prescribed by the commissioner, to have the amount of the overpayment refunded to him or to have the amount credited against the payment which he is required to make for a subsequent quarterly period, but the refund or credit shall be allowed only to the extent that the amount of the overpayment was not withheld under Section 27-7-305 by the employer.

(2) If the commissioner shall determine that the employer is not entitled to the refund or credit as applied for, he shall so notify the employer of the denial of the refund claim.

(3) Unless written application for refund or credit is received by the commissioner from the employer within three (3) years from the date the overpayment was made, no refund or credit shall be allowed.