Section 1814. Designation of defendant; amendment procedure

(a)  A party who is ignorant, in whole or in part, of the true name of
  a person, partnership, firm or corporation which may properly be made  a
  party  defendant, may proceed against such defendant in any name used by
  the person, partnership, firm or corporation in conducting business,  as
  defined  in subdivision (a) of section eighteen hundred thirteen of this
  article.
    (b) If the true name of the defendant becomes known at any time  prior
  to  the  hearing on the merits, such information shall be brought to the
  attention  of  the  clerk,  who  shall  immediately  amend   all   prior
  proceedings  and  papers.  The clerk shall send an amended notice to the
  defendant, without payment of additional fees by the plaintiff, and  all
  subsequent proceedings and papers shall be amended accordingly.
    (c)  In  every  action in the small claims part, at the hearing on the
  merits, the judge or arbitrator shall  determine  the  defendant's  true
  name.  The clerk shall amend all prior proceedings and papers to conform
  to such determination, and all subsequent proceedings and  papers  shall
  be amended accordingly.
    (d)  A party against whom a judgment has been entered pursuant to this
  article, in any proceeding under section five thousand  fifteen  of  the
  civil  practice  law  and  rules  for  relief from such judgment, shall,
  disclose its true name; any and all names  in  which  it  is  conducting
  business;  and  any and all names in which it was conducting business at
  the time of the transaction or occurrence  on  which  such  judgment  is
  based. All subsequent proceedings and papers shall be amended to conform
  to such disclosure.