(1) If any overpayment of any tax, interest or penalty levied or provided for by Article 1 of this chapter, or in this article, is not refunded to the taxpayer as provided in Section 27-7-313 within six (6) months after the final date for filing returns as prescribed by law, the taxpayer may treat the failure to refund as a denial of a refund claim and appeal in the manner provided for in Section 27-77-5. A taxpayer’s failure to file an appeal based on this deemed denial shall not prejudice or otherwise jeopardize the taxpayer’s right to file an appeal upon a subsequent formal denial in the manner provided for in Section 27-77-5.

(2) If any overpayment of tax as reflected on a return, amended return or any other form of claim for refund or determined to be due by the commissioner or department when no overpayment is shown on a return, amended return or other form of claim for refund, is not refunded within ninety (90) days after (a) the prescribed due date of the return, (b) the date the return is filed, (c) the date a claim for refund is filed, or (d) the date the commissioner, the Board of Tax Appeals or court determines a refund as being due when no overpayment is shown on a return, amended return or other form of claim for refund, whichever is later, interest at the rate of one percent (1%) per month, except as otherwise provided in this section, shall be allowed on the overpayment computed for the period after expiration of the ninety-day period provided in this subsection to the date of payment. For any overpayment reflected on a return or amended return filed on or after January 1, 2015, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2015, where no overpayment is shown on a return or amended return, the rate of interest allowed on the overpayment shall be:

(a) Nine-tenths of one percent (9/1 of 1%) per month for any overpayment reflected on a return or amended return filed on or after January 1, 2015, and before January 1, 2016, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2015, and before January 1, 2016, where no overpayment is shown on a return or amended return;

(b) Eight-tenths of one percent (8/1 of 1%) per month for any overpayment reflected on a return or amended return filed on or after January 1, 2016, and before January 1, 2017, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2016, and before January 1, 2017, where no overpayment is shown on a return or amended return;

(c) Seven-tenths of one percent (7/1 of 1%) per month for any overpayment reflected on a return or amended return filed on or after January 1, 2017, and before January 1, 2018, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2017, and before January 1, 2018, where no overpayment is shown on a return or amended return;

(d) Six-tenths of one percent (6/1 of 1%) per month for any overpayment reflected on a return or amended return filed on or after January 1, 2018, and before January 1, 2019, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2018, and before January 1, 2019, where no overpayment is shown on a return or amended return;

(e) One-half of one percent (½ of 1%) per month for any overpayment reflected on a return or amended return filed on or after January 1, 2019, or any overpayment based on a determination of refund by the commissioner, the Board of Tax Appeals or court on or after January 1, 2019, where no overpayment is shown on a return or amended return.