§ 131. Limitations on assessment. (a) General.--Except as otherwise
provided in this section, any tax under this title shall be assessed
within three years after the return was filed (whether or not such
return was filed on or after the date prescribed).

(b) Time return deemed filed.--For purposes of this section a return
of income tax filed before the last day prescribed by law or by
regulations promulgated pursuant to law for the filing thereof, shall be
deemed to be filed on such last day.

(c) Exceptions.--(1) Assessment at any time.--The tax may be assessed
at any time if--

(A) no return is filed,

(B) a false or fraudulent return is filed with intent to evade tax,

(C) the taxpayer fails to comply with section one hundred twenty-seven
in not reporting a change or correction increasing or decreasing his
federal taxable income as reported on his federal income tax return, or
the execution of a notice of waiver and the changes or corrections on
which it is based or in not reporting a change or correction which is
treated in the same manner as if it were a deficiency for federal income
tax purposes, or in not filing an amended return, or

(D) the taxpayer fails to file a report or amended return or report
required under section one hundred twenty-seven-A, in respect of a
change or correction of sales and compensating use tax liability,
relating to the purchase or use of items for which a sales or
compensating use tax credit against the tax imposed by this title was
claimed.

(2) Extension by agreement.--Where, before the expiration of the time
prescribed in this section for the assessment of tax, both the director
of finance and the taxpayer have consented in writing to its assessment
after such time, the tax may be assessed at any time prior to the
expiration of the period agreed upon. The period so agreed upon may be
extended by subsequent agreements in writing made before the expiration
of the period previously agreed upon.

(3) Report of changed or corrected federal income. If the taxpayer
shall, pursuant to section one hundred twenty-seven, report a change or
correction or file an amended return increasing or decreasing his
federal taxable income or report the execution of a notice of waiver and
the changes and corrections on which it is based, or a change or
correction which is treated in the same manner as if it were a
deficiency for federal income tax purposes, the assessment (if not
deemed to have been made upon the filing of the report or amended
return) may be made at any time within two years after such report or
amended return was filed. The amount of such assessment of tax shall not
exceed the amount of the increase in city tax attributable to such
federal change or correction. The provisions of this paragraph shall not
affect the time within which or the amount for which an assessment may
otherwise be made.

(4) Deficiency attributable to net operating loss carryback.--If a
deficiency is attributable to the application to the taxpayer of a net
operating loss carryback, it may be assessed at any time that a
deficiency for the taxable year of the loss may be assessed.

(5) Recovery of erroneous refund.--An erroneous refund shall be
considered an underpayment of tax on the date made, and an assessment of
a deficiency arising out of an erroneous refund may be made at any time
within two years from the making of the refund, except that the
assessment may be made within five years from the making of the refund
if it appears that any part of the refund was induced by fraud or
misrepresentation of a material fact.

(6) Request for prompt assessment.--If a return is required for a
decedent or for his estate during the period of administration, the tax
shall be assessed within eighteen months after written request therefor
(made after the return is filed) by the executor, administrator or other
person representing the estate of such decedent, but not more than three
years after the return was filed, except as otherwise provided in this
subdivision and subdivision (d).

(7) Report on use of certain property.--Under the circumstances
described in paragraph two of subdivision (b) of section one hundred
eight, the tax may be assessed within three years after the filing of a
return reporting that property has been used for purposes other than
research and development to a greater extent than originally reported.

(8) Report concerning waste treatment facility.--Under the
circumstances described in paragraph (9) of section one hundred six, the
tax may be assessed within three years after the filing of the return
containing the information required by such paragraph.

(9) Report of change or corrected sales and compensating use tax
liability.--If the taxpayer files a report or amended return or report
required under section one hundred twenty-seven-A, in respect of a
change or correction of sales and compensating use tax liability, the
assessment (if not deemed to have been made upon the filing of the
report) may be made at any time within two years after such report or
amended return or report was filed. The amount of such assessment of tax
shall not exceed the amount of the increase in city tax attributable to
such state change or correction. The provisions of this paragraph shall
not affect the time within which or the amount for which an assessment
may otherwise be made.

(d) Omission of income on return.--The tax may be assessed at any time
within six years after the return was filed if (1) a taxpayer omits from
his city unincorporated business gross income an amount properly
includible therein which is in excess of twenty-five per centum of the
amount of city unincorporated business gross income stated in the
return, or (2) an estate or trust omits income from its return in an
amount in excess of twenty-five per cent of its income determined as if
it were an individual.

For purposes of this subdivision there shall not be taken into account
any amount which is omitted in the return if such amount is disclosed in
the return, or in a statement attached to the return, in a manner
adequate to apprise the director of finance of the nature and amount of
such item.

(e) Suspension of running of period of limitation.--The running of the
period of limitations on assessment or collection of tax or other amount
(or of a transferee's liability) shall, after the mailing of a notice of
deficiency, be suspended for the period during which the director of
finance is prohibited under subdivision (c) of section one hundred
twenty-nine from making the assessment or from collecting by levy.