§ 132. Interest on underpayment. (a) General.--If any amount of income
tax is not paid on or before the last date prescribed in this title for
payment, interest on such amount at the rate set by the commissioner of
finance pursuant to section one hundred forty-five, or, if no rate is
set, 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.

(b) Exception as to estimated tax.--This section shall not apply to
any failure to pay estimated tax under section one hundred sixteen.

(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 title (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.

(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 director of finance 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 filing date for the taxable year
in which the net operating loss arises. Such filing date shall be
determined without regard to extensions of time to file.

(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 title 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 one hundred forty, 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 one hundred twenty-nine, the director of finance 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 director of finance, 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 one hundred twenty-nine 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 one hundred forty, 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
commissioner of finance, shall bear interest at the rate set by the
commissioner of finance pursuant to section one hundred forty-five, or,
if no rate is set, 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.