Comparison of a disputed writing with any writing proved to the satisfaction of the court to be the handwriting of the person claimed to have made the disputed writing shall be permitted.
R 4536.Proof of writing by comparison of handwriting.
Article 45. Evidence · Last amended 1963 · Last verified July 21, 2026
In one sentenceCPLR 4536 allows a disputed writing's authenticity to be proven by comparing it side by side with another writing that the court is satisfied is genuine, opening the door to expert or lay handwriting comparison at trial.
Full Text of CPLR 4536
Plain-English Summary
Before this rule, New York courts distrusted handwriting comparison as a method of proof, a legacy of old common-law skepticism toward jurors and witnesses guessing at penmanship. CPLR 4536 abandons that skepticism. It permits a party to prove that a disputed document was written by a particular person by placing it next to another writing the court is satisfied is that person's handwriting, and inviting the fact-finder, often through an expert witness, to compare the two.
The rule does not tell a party how to establish that the comparison sample is genuine; that showing still has to satisfy the court through independent proof, such as testimony from someone familiar with the person's handwriting or other authentication evidence. Once that foundation is laid, the comparison itself becomes admissible, and the weight it carries is up to the jury or judge.
Handwriting comparison surfaces most often in will contests, contract disputes over signatures, and cases alleging forgery. CPLR 4536 gives parties a clear path to make that argument instead of leaving authenticity to rest on a single witness's say-so.
Frequently Asked Questions
Do I need an expert witness to compare handwriting under CPLR 4536?
The statute does not require one, but courts and juries usually give more weight to a qualified handwriting expert's comparison than to a lay opinion.
How do I prove the comparison sample itself is genuine?
You need separate evidence, such as testimony from a witness familiar with the person's handwriting, that satisfies the court the sample writing is authentic before the comparison can go forward.
Can CPLR 4536 be used to challenge a signature on a contract?
Yes. A party disputing a signature can offer a known genuine writing from the same person and ask the fact-finder to compare it with the disputed signature.
Is handwriting comparison evidence used in will contests?
It comes up often in will contests, where a party challenges whether the testator signed the document.
Did New York always allow handwriting comparison as proof?
No. Common-law courts were wary of comparison evidence, and CPLR 4536 codifies the modern rule that permits it once the comparison writing's authenticity is established.
Advisory Committee Notes
This rule is the same as former § 332, except for a number of minor language changes.
Amendment History
Formerly § 4536, add, L 1962, ch 308; amd, L 1962, ch 315, § 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
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