Section 11-531. Mailing rules; holidays; miscellaneous

(a) Timely mailing.
  (1) If any return,  declaration  of  estimated  tax,  claim,  statement,
  notice, petition, or other document required to be filed, or any payment
  required  to  be  made,  within  a  prescribed  period or on or before a
  prescribed date under authority of any provision  of  this  chapter  is,
  after  such  period or such date, delivered by the United States mail to
  the commissioner of  finance,  tax  appeals  tribunal,  bureau,  office,
  officer  or  person with which or with whom such document is required to
  be filed, or to which or to whom such payment is required  to  be  made,
  the  date of the United States postmark stamped on the envelope shall be
  deemed to be the date of delivery. This subdivision shall apply only  if
  the postmark date falls within the prescribed period or on or before the
  prescribed  date  for  the  filing  of  such document, or for making the
  payment, including any extension granted for such filing or payment, and
  only if such document or payment was  deposited  in  the  mail,  postage
  prepaid,  properly addressed to the commissioner of finance, tax appeals
  tribunal, bureau, office, officer or person with which or with whom  the
  document  is required to be filed or to which or to whom such payment is
  required to be made. If any document is sent by United States registered
  mail, such registration shall be prima facie evidence that such document
  was delivered to the commissioner  of  finance,  tax  appeals  tribunal,
  bureau,  office, officer or person to which or to whom addressed. To the
  extent that the commissioner of finance  or,  where  relevant,  the  tax
  appeals  tribunal  shall  prescribe by regulation, certified mail may be
  used in lieu of registered mail under this section. Except  as  provided
  in  paragraph  two  of this subdivision, this subdivision shall apply in
  the case of postmarks not made by the United States postal service  only
  if  and  to  the  extent  provided by regulations of the commissioner of
  finance or, where relevant, the tax appeals tribunal.
    (2) (A) Any reference in paragraph one  of  this  subdivision  to  the
  United  States  mail  shall  be  treated as including a reference to any
  delivery service designated by the secretary  of  the  treasury  of  the
  United  States  pursuant  to  section  seventy-five  hundred  two of the
  internal revenue code  and  any  reference  in  paragraph  one  of  this
  subdivision  to a United States postmark shall be treated as including a
  reference to any date recorded or marked  in  the  manner  described  in
  section  seventy-five  hundred  two  of  the  internal revenue code by a
  designated delivery service. If the commissioner of finance  finds  that
  any  delivery service designated by such secretary is inadequate for the
  needs of the city, the commissioner may withdraw  such  designation  for
  purposes  of  this title. The commissioner may also designate additional
  delivery services meeting the criteria of section  seventy-five  hundred
  two  of  the  internal  revenue  code for purposes of this title, or may
  withdraw any such designation if the commissioner of finance finds  that
  a  delivery  service  so  designated  is inadequate for the needs of the
  city. Any reference in paragraph one of this subdivision to  the  United
  States  mail  shall  be treated as including a reference to any delivery
  service designated by the commissioner of finance and any  reference  in
  paragraph  one  of this subdivision to a United States postmark shall be
  treated as including a reference to any date recorded or marked  in  the
  manner  described  in  section  seventy-five hundred two of the internal
  revenue code by a delivery service designated  by  the  commissioner  of
  finance.    Notwithstanding the foregoing, any withdrawal of designation
  or additional designation by the commissioner of finance  shall  not  be
  effective  for purposes of service upon the tax appeals tribunal, unless
  and until such withdrawal of designation or  additional  designation  is
  ratified by the president of the tax appeals tribunal.

    (B)  Any  equivalent of registered or certified mail designated by the
  United States secretary of the treasury, or as may be designated by  the
  commissioner  of  finance  pursuant  to  the  same criteria used by such
  secretary for such designations pursuant to section seventy-five hundred
  two  of  the internal revenue code, shall be included within the meaning
  of registered or certified  mail  as  used  in  paragraph  one  of  this
  subdivision. If the commissioner of finance finds that any equivalent of
  registered  or  certified  mail  designated  by  such  secretary  or the
  commissioner of finance is inadequate for the needs  of  the  city,  the
  commissioner  of  finance  may withdraw such designation for purposes of
  this title. Notwithstanding the foregoing, any withdrawal of designation
  or additional designation by the commissioner of finance  shall  not  be
  effective  for purposes of service upon the tax appeals tribunal, unless
  and until such withdrawal of designation or  additional  designation  is
  ratified by the president of the tax appeals tribunal.
    (b)  Last  known  address.  For purposes of this chapter, a taxpayer's
  last known address shall be given  in  the  last  return  filed  by  the
  taxpayer,  unless subsequently to the filing of such return the taxpayer
  shall have notified the commissioner of finance of a change of address.
    (c) Last day a Saturday, Sunday or legal holiday. When  the  last  day
  prescribed  under  authority of this chapter (including any extension of
  time) for performing any act falls  on  Saturday,  Sunday,  or  a  legal
  holiday  in  the state of New York, the performance of such act shall be
  considered timely if it is performed on the next succeeding day which is
  not a Saturday, Sunday or legal holiday.
    (d) Certificate: unfiled return. For  purposes  of  this  chapter  and
  sections  one hundred sixty-eight through one hundred seventy-two of the
  charter, the certificate of the commissioner of finance  to  the  effect
  that  a tax has not been paid, that a return or declaration of estimated
  tax has not been filed, or that information has not  been  supplied,  as
  required  by or under the provisions of this title, shall be prima facie
  evidence  that  such  tax  has  not  been  paid,  that  such  return  or
  declaration  has  not  been filed, or that such information has not been
  supplied.