§ 1084. Interest on underpayment.---(a) General.--If any amount of tax
is not paid on or before the last date prescribed in article nine or
nine-a of this chapter for payment, interest on such amount at the
underpayment rate set by the commissioner pursuant to section one
thousand ninety-six of this article, or if no rate is set, at the rate
of seven and one-half percent 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 subsection shall not
be paid if the amount thereof is less than one dollar.

(b) Exception as to estimated tax.---This section shall not apply to
any failure to pay estimated tax under article nine-a, nine-b or nine-c.

(c) Exception for mathematical or clerical error.--- No interest shall
be imposed on any underpayment of tax due solely to mathematical or
clerical error if the taxpayer files a return within the time prescribed
in article nine or nine-A (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) 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 tax commission 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.

(e) Tax reduced by carryback.---If the amount of tax under article
nine-a for any taxable year is reduced by reason of a carryback of a net
operating loss or a capital loss, such reduction in tax shall not affect
the computation of interest under this section for the period ending
with the filing date for the taxable year in which the net operating
loss or capital loss arises. Such filing date shall be determined
without regard to extensions of time to file.

(f) 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 the tax under article nine, nine-a, nine-b or nine-c.
Any reference in this article to the tax imposed by article nine,
nine-a, nine-b or nine-c shall be deemed also to refer to interest
imposed by this section on such tax.

(g) Interest on penalties or additions to tax.---Interest shall be
imposed under subsection (a) of this section in respect of any
assessable penalty or addition to tax only if such assessable penalty or
addition to tax is not paid within twenty-one calendar days from the
date of the notice and demand therefor under subsection (b) of section
one thousand ninety-two of this article (ten business days if the amount
for which such notice and demand is made equals or exceeds one hundred
thousand dollars) 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.

(h) Payment within specified period after notice and demand.---If
notice and demand is made for payment of any amount under subsection (b)
of section one thousand ninety-two of this article, and if such amount
is paid within twenty-one calendar days (ten business days if the amount
for which such notice and demand is made equals or exceeds one hundred
thousand dollars) 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.

(i) 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.

(j) Interest on erroneous refund.---Any portion of tax or other amount
which has been erroneously refunded, and which is recoverable by the
commissioner, shall bear interest at the underpayment rate set by the
commissioner pursuant to section one thousand ninety-six of this
article, or if no rate is set, at the rate of seven and one-half percent
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.

(k) 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.