(a) All taxes imposed and all moneys withheld by employers, under this Chapter, and remaining unpaid after they have become due shall bear interest, in addition to the amount of the unpaid tax or withholdings, at the rate of twelve percent (12%) per year.
(b) In addition to the interest provided in subsection (a) hereof, penalties for nonpayment of taxes and moneys required to be withheld by employers, under this Chapter are hereby imposed as follows:
(1) In the case of a taxpayer upon whom such taxes are imposed, the penalty shall be ten percent (10%) of the unpaid tax, if paid during the first (1st) month after the same becomes due, and two percent (2%) additional per month or fraction thereof after the first (1st) month. The maximum penalty under this subsection shall not exceed twenty percent (20%). However, no penalty shall be assessed on an additional tax assessment made by the Director of Taxation when a return has been filed in good faith and the tax paid thereon within the time prescribed herein. No penalty or interest shall be assessed on any additional tax assessment resulting from a Federal audit, provided that an amended return is filed and the additional tax paid within three (3) months after the final determination of Federal tax liability.
(2) In the case of an employer required to withhold taxes from employees under this Chapter, the penalty shall be ten percent (10%) of the unpaid withholding, if paid during the first (1st) month after the same becomes due, and three percent (3%) additional per month or fraction thereof after the first (1st) month. The maximum penalty under this subsection shall not exceed twenty-five (25%) percent.
(c) Upon recommendation of the Director of Taxation, the Board of Review may abate the penalties and interest, or both. Upon appeal from the refusal of the Director of Taxation to recommend abatement of the penalties or interest, the Board of Review may nevertheless abate the penalties or interest, or both.