When relief against a mistake is sought in an action or by way of defense or counterclaim, relief shall not be denied merely because the mistake is one of law rather than one of fact.
§ 3005.Relief against mistake of law
Article 30. Remedies and Pleading · Last amended 1963 · Last verified July 21, 2026
In one sentenceCPLR 3005 tells New York courts not to withhold relief for a mistake solely because that mistake was about the law rather than the facts.
Full Text of CPLR 3005
Plain-English Summary
Courts long treated mistakes of fact and mistakes of law differently. A party who misunderstood a fact — thinking a ring was gold when it was brass — could often get relief; a party who misunderstood the law governing rights or obligations often couldn't, on the idea that everyone is presumed to know the law. That presumption rarely matched reality, and it produced results that had little to do with whether the mistake mattered.
CPLR 3005 erases that distinction for purposes of getting relief. When relief against a mistake is sought in an action, or by way of defense or counterclaim, it can't be denied merely because the mistake was one of law instead of fact. The court has to look at the mistake on its own terms rather than filter it through which category it falls into.
Frequently Asked Questions
Can I get relief in a New York lawsuit for a mistake about the law?
Yes. CPLR 3005 says relief will not be denied merely because the mistake is one of law rather than one of fact.
What's the difference between a mistake of law and a mistake of fact under CPLR 3005?
A mistake of fact involves being wrong about a circumstance, such as what an item is; a mistake of law involves being wrong about what the law requires or permits, and the section treats both the same way.
Why did courts used to refuse relief for mistakes of law?
Courts relied on a presumption that everyone knows the law, which made a mistaken legal belief look like something the mistaken party should be held to regardless of the actual circumstances.
Does CPLR 3005 apply to defenses and counterclaims, not just claims?
Yes. The section applies whenever relief against a mistake is sought in an action or by way of defense or counterclaim.
Does CPLR 3005 guarantee I'll win if I made a legal mistake?
No. It only removes the categorical bar against relief for a mistake of law; the court still decides the case on its merits.
Advisory Committee Notes
Except for a minor language change, this section is the same as CPA § 112-f, enacted in 1942. Laws 1942, c 558.
Amendment History
Add, L 1962, ch 308, § 1, eff Sept 1, 1963.
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
Also known as: mistake of law New York lawsuitrelief for legal mistake CPLRmistake of law vs fact New Yorkignorance of the law defense CPLR