Section 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.