§ 64. Interest on underpayment.--(a) General.--If any amount of income tax is not paid on or before the last date prescribed in this local law for payment, interest on such amount at the rate of six percentum per annum shall be paid for the period from such last date to the date paid, whether or not any extension of time for payment was granted. Interest under this subdivision shall not be paid if the amount thereof is less than one dollar. If the time for filing a return of tax withheld by an employer is extended, the employer shall pay interest for the period for which the extension is granted and may not charge such interest to the employee.(b) Exception as to estimated tax.--This section shall not apply to any failure to pay estimated tax under section thirty-six.
(c) Exception for mathematical error.--No interest shall be imposed on any underpayment of tax due solely to mathematical error if the taxpayer files a return within the time prescribed in this local law (including any extension of time) and pays the amount of underpayment within three months after the due date of such return, as it may be extended.
(d) No interest on interest.--No interest under this local law shall be imposed on any interest provided by this title.
(e) Suspension of interest on deficiencies.--If a waiver of restrictions on assessment of a deficiency has been filed by the taxpayer, and if notice and demand by the administrator for payment of such deficiency is not made within thirty days after the filing of such waiver, interest shall not be imposed on such deficiency for the period beginning immediately after such thirtieth day and ending with the date of notice and demand.
(f) Tax reduced by carryback.--If the amount of tax for any taxable year is reduced by reason of a carryback of a net operating loss, such reduction in tax shall not affect the computation of interest under this section for the period ending with the last day of the taxable year in which the net operating loss arises.
(g) Interest treated as tax.--Interest under this section shall be paid upon notice and demand and shall be assessed, collected and paid in the same manner as income tax. Any reference in this title to the tax imposed by this local law shall be deemed also to refer to interest imposed by this section on such tax.
(h) Interest on penalties or additions to tax.--Interest shall be imposed under subdivision (a) in respect of any assessable penalty or addition to tax only if such assessable penalty or addition to tax is not paid within ten days from the date of the notice and demand therefor under subdivision (b) of section seventy-two, and in such case interest shall be imposed only for the period from such date of the notice and demand to the date of payment.
(i) Payment prior to notice of deficiency.--If, prior to the mailing to the taxpayer of a notice of deficiency under subdivision (b) of section sixty-one, the administrator mails to the taxpayer a notice of proposed increase of tax and within thirty days after the date of the notice of proposed increase the taxpayer pays all amounts shown on the notice to be due to the administrator, no interest under this section on the amount so paid shall be imposed for the period after the date of such notice of proposed increase.
(j) Payment within ninety days after notice of deficiency.--If a notice of deficiency under section sixty-one is mailed to the taxpayer, and the total amount specified in such notice is paid on or before the ninetieth day after the date of mailing, interest under this section shall not be imposed for the period after the date of the notice.
(k) Payment within ten days after notice and demand.--If notice and demand is made for payment of any amount under subdivision (b) of section seventy-two, and if such amount is paid within ten days after the date of such notice and demand, interest under this section on the amount so paid shall not be imposed for the period after the date of such notice and demand.
(l) Limitation on assessment and collection.--Interest prescribed under this section may be assessed and collected at any time during the period within which the tax or other amount to which such interest relates may be assessed and collected, respectively.
(m) Interest on erroneous refund.--Any portion of tax or other amount which has been erroneously refunded, and which is recoverable by the administrator, shall bear interest at the rate of six per centum per annum from the date of the payment of the refund, but only if it appears that any part of the refund was induced by fraud or a misrepresentation of a material fact.
(n) Satisfaction by credits.--If any portion of a tax is satisfied by credit of an overpayment, then no interest shall be imposed under this section on the portion of the tax so satisfied for any period during which, if the credit had not been made, interest would have been allowable with respect to such overpayment.
