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§ 2001.Mistakes, omissions, defects and irregularities.

Article 20. Mistakes, Defects, Irregularities and Extensions of Time · Last amended 2007 · Last verified July 21, 2026

In one sentenceCPLR 2001 gives courts broad power to correct -- or disregard outright -- a mistake, omission, defect, or irregularity at any stage of a case, including in the papers used to start it, as long as no substantial right of a party is prejudiced.

Full Text of CPLR 2001

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At any stage of an action, including the filing of a summons with notice, summons and complaint or petition to commence an action, the court may permit a mistake, omission, defect or irregularity, including the failure to purchase or acquire an index number or other mistake in the filing process, to be corrected, upon such terms as may be just, or, if a substantial right of a party is not prejudiced, the mistake, omission, defect or irregularity shall be disregarded, provided that any applicable fees shall be paid.

Plain-English Summary

Litigation runs on paperwork, and paperwork gets things wrong -- a missing index number, a defective caption, a step skipped in commencing the case. CPLR 2001 keeps those errors from derailing a case that's otherwise sound. At any stage of an action, including the filing of a summons with notice, a summons and complaint, or a petition that starts the case, a court can permit the mistake to be corrected on whatever terms are just.

Where a substantial right of a party isn't at stake, the court doesn't even need to grant a formal motion to fix it -- the statute directs that the defect be disregarded instead. The section specifically covers the failure to purchase or acquire an index number among the correctable filing mistakes, closing off arguments that a missed-index-number error alone should doom an otherwise valid filing. One condition survives every correction: any fee that should have been paid still has to be paid.

Frequently Asked Questions

Can a court fix a mistake in how a lawsuit was filed in New York?

Yes. CPLR 2001 lets a court permit correction of a mistake, omission, defect, or irregularity at any stage of an action, including in the papers used to commence it.

What happens if a party forgot to purchase an index number in New York?

CPLR 2001 specifically covers the failure to purchase or acquire an index number as a correctable filing mistake, as long as the required fee gets paid and no substantial right is prejudiced.

Does a court have to grant a motion to fix a minor filing error?

Not always. If a substantial right of a party isn't prejudiced, CPLR 2001 directs that the mistake, omission, defect, or irregularity be disregarded rather than requiring formal correction.

Does CPLR 2001 excuse unpaid filing fees?

No. Even when a mistake is corrected or disregarded under CPLR 2001, any fee that should have been paid must still be paid.

What counts as a substantial right under CPLR 2001?

The statute doesn't define the phrase with a fixed list; a court looks at whether the error harmed a party's ability to litigate the case, as opposed to a technical slip with no real consequence.

Advisory Committee Notes

This section is taken from CPA § 105 with only minor verbal changes. Cf. Fed R Civ P 51. The formulation was selected by the authors of CPA as the broadest of a number of proposals. See Report of the Joint Legislative Committee on the Simplification of Civil Practice 107–08 (1919). It appears to work well in practice.

A number of the new CPLR provisions cover mistakes and irregularities in particular situations. Thus, § 325(a) corresponding to part of CPA § 110, allows removal for the mistake of instituting an action in an improper court; §§ 509–511, corresponding to CPA §§ 186 and 187, allow either trial in the improper county or change of the place of trial where the wrong venue is chosen; and § 5019(a), derived from CPA § 109, declares that a judgment shall not be stayed or impaired by any mistake or defect in the papers or procedures not affecting a substantial right.

The Committee approved this measure in 2006 after the printing and distribution of the 2006 Report. The proposal was introduced in the Legislature and was received favorably in the Assembly with passage in June 2006. It is introduced as a new measure in the 2007 Report without change.

This measure, which would amend CPLR 2001, is offered in response to a series of recent decisions by the Court of Appeals, which have held that defects in the commencement of actions or the payment of the fee for an index number will result in outright dismissal of an action so long as a timely objection is made to such defects, See Matter of Harris v. Niagara Falls Bd. of Education , 6 N.Y.3d 155 (2006); Matter of Gershel v. Porr , 89 N.Y.2d 327 (1996); Matter of Fry v. Village of Tarrytown , 80 N.Y.2d 714 (1997). 1 1 These court decisions signal a need to revise CPLR 2001 to harmonize it with the underlying purpose of chapter 216 of the Laws of 1992. Although the Legislature initially acted in that year to raise revenue by requiring payment of a fee for an index number before an action could proceed, the Legislature subsequently made numerous changes to the CPLR in that same session to initiate commencement by filing to further the separate policy goal of eliminating the dismissal of cases because of non-prejudicial defects in such commencement. Unfortunately, as 1 In Harris, the Court dismissed an action because plaintiff filed the summons and complaint under the same index number that was used to make a motion to serve a late notice of claim and despite the fact that the failure to purchase a second index number caused defendant no prejudice or delay of the action. In Gershel, petitioner served a second action after voluntarily withdrawing the first one, but failed to file a new set of papers or to pay the filing fee. Once again, despite, the fact that no prejudice was shown, the proceeding was dismissed. In Fry, petitioner paid the filing fee and filed an unexecuted order to show cause and petition with the clerk of the court. Despite the fact that, under court procedures, the petitioner could not present the order to a judge for signing before filing the papers and paying the fee, the Court held that the filing of an unexecuted order to show cause did not comply with the CPLR and held that the action was dismissible. The action was not dismissed only because the respondent had failed to make a timely objection.

evidenced by these recent decisions, it is apparent that further statutory revision is in order to fully foreclose dismissal of actions for technical, non prejudicial defects.

Accordingly, this measure would amend the CPLR to give the court discretion to correct or ignore mistakes or omissions occurring at the commencement of an action that do not prejudice the opposing party, in the same manner and under the same standards that is already does with regard to all other non-prejudicial procedural events.

It is important to emphasize that this measure would not excuse a complete failure to file within the statute of limitations. Moreover, in order to properly commence an action, a plaintiff or petitioner would still have to actually file a summons and complaint or a petition. A bare summons, for example, would not constitute a filing. The purpose of this measure is to clarify that a mistake in the method of filing, as opposed to a mistake in what is filed , is a mistake subject to correction in the court’s discretion. In this respect we do not intend to overrule the Court of Appeals’ precedent in Parker v, Mack 61 N.Y.2d 114 (1984). However, other non-prejudicial defects in commencement, such as late payment of the fee because of a bounced check (which is subsequently cured) or the failure to purchase a second index number under the facts of Harris would be excusable deficiencies. Finally, this measure would not result in any loss of revenue to the State from the payment of fees for index numbers. When presented with a motion to dismiss for failure to pay the fee, the court must condition denial of the motion on plaintiff’s payment of the proper fee.

This measure, which would have no fiscal impact on the State, would take effect immediately.

Amendment History

Add, L 1962, ch 308, § 1, eff Sept 1, 1963; amd, L 2007, ch 529, § 1, eff Aug 15, 2007.

Source & verification. Provision text, History, and Advisory Committee Notes are reproduced verbatim from the Consolidated Laws of New York. Last verified July 21, 2026. · Official source
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