2015 New York Laws
GCT - General City
Article 2-D - (General City) CITY PERSONAL INCOME TAX ON RESIDENTS
25-A - Authorization to impose tax.

 25-a. Authorization to impose tax.-- In addition to any other taxes,
  now  authorized  by  law, any city having a population of one million or
  more is hereby authorized and empowered to adopt and  amend  local  laws
  imposing  a  tax  on the personal income of residents of such city to be
  administered  in  the  manner  provided  for  in  this  article  by  the
  administrator  as  defined  in  section  one  of  the  model  local  law
  hereinafter set forth.
The tax authorized by this article may be imposed only if the  general
  city  law  authorizes  the  adoption  of  a  city tax on the earnings of
  nonresidents and the  city  imposing  the  tax  herein  authorized  also
  imposes  such tax on the earnings of nonresidents. The rates of such tax
  shall be the rates contained in either section three or three-A  of  the
  model  local  law  and such rates may be reduced and increased, provided
  that the rates shall not be fixed higher than those contained in section
  three-A of such model local law.
The terms of such local law shall be substantially  the  same  as  the
  following model local law except that:
(a) Any such local law may include a provision for the specific credit
  for  individuals  described  in  section  twenty-five-b  of this chapter
  effective for any taxable  year  commencing  on  or  after  July  first,
  nineteen hundred sixty-seven;
(b)  Any  such  local  law  may  be amended to conform it with similar
  provisions of article twenty-two of the tax law  except  insofar  as  it
  relates  to nonresidents as presently in effect or as it may be amended;
  and
(c) The appendix in such local law may be amended for the  purpose  of
  conforming  it  with  the  United  States internal revenue code or other
  federal laws relating to taxation as presently in effect or as they  may
  be amended.