(a) Credit. The amount of tax deducted or withheld during any calendar year with respect to an employee shall be allowed as a credit to the employee against his income tax liability under Code Section 48-7-20 for the taxable year beginning in the calendar year.

(b) Overpayment.

(1) To the extent that the credit provided in subsection (a) of this Code section together with other credits allowed by law is in excess of the employee's income tax liability for the taxable year as shown on an income tax return filed by the employee for that year, the overpayment shall be considered as taxes erroneously paid and shall be credited or refunded as provided in this Code section. An overpayment shall be credited to the person's estimated income tax liability for the succeeding taxable year unless the person claims a refund for the overpayment. The commissioner may consider any final return showing an overpayment as a claim for refund per se. An overpayment shall bear no interest if credit is given for the overpayment. Amounts refunded as overpayments shall bear interest at the rate provided in Code Section 48-2-35 but only after 90 days from the filing date of the final return showing the overpayment or from the due date of the final return, whichever is later.

(2) A refund shall be deemed to have been made when the commissioner issues a check for the refund payable to the claimant. The record in the office of the commissioner as to the time of issuance of the refund shall be prima-facie evidence of the time the refund is made. Whenever a check is issued for a refund claimed or shown due on a final return and no separate claim has been filed for the refund, the check shall be sent by first-class mail to the claimant at the address shown on the return in an envelope instructing return of the envelope if not delivered in ten days. The commissioner shall publish in print or electronically the names of claimants whose checks are returned. If a refund check is not claimed in accordance with the commissioner's instructions within 90 days after the publication, the refund claim covered by the check shall be deemed to have been abandoned. Any refund check which is not presented for payment within 180 days after the date of the check shall be void and the refund claim covered by the check shall be deemed to have been abandoned. When any claim for refund has been abandoned, any funds which may have been designated or set aside for its payment shall be returned to the Office of the State Treasurer and the claimant's right to the refund shall be barred. This subsection shall not apply to a claim for refund filed with, but separately from, a final return under general law and shall not affect the period of limitations allowed by general law applicable to a claim for refund when filed separately from a final return.

(c) Limitation on refund or credit. No refund or credit shall be allowed unless the employee attaches to and files with his final income tax return a copy of the employer's receipt as provided for in Code Section 48-7-105 for the amount of tax deducted and withheld from his wages for that taxable year. If an employee submits satisfactory proof that his employer deducted and withheld taxes from his wages and that the employer failed or refused to furnish the employee with the prescribed receipt, the proof so furnished may be taken to establish a credit or refund under this Code section.

(d) Setoffs. Notwithstanding any other provision of this subsection, a refund or a portion thereof may be transferred to a claimant agency to set off a debt due and owing to the claimant agency as provided in Article 7 of this chapter. When any action pursuant to Article 7 of this chapter is taken, that article shall govern all aspects of right and entitlement to refunds covered thereunder. Funds transferred to claimant agencies shall not bear interest. If there is a final determination that the taxpayer alleged to be a debtor is entitled to receive all or part of the funds transferred to a claimant agency, the amount to which the taxpayer is entitled shall bear interest at the rate provided in Code Section 48-2-35 beginning 30 days after the final determination.