Except as otherwise expressly prescribed, a person shall not be excluded or excused from being a witness, by reason of his interest in the event or because he is a party or the spouse of a party.
§ 4512.Competency of interested witness or spouse
Article 45. Evidence · Last amended 1963 · Last verified July 21, 2026
In one sentenceCPLR 4512 abolishes the old common-law rule disqualifying witnesses for being interested in the outcome, a party, or a party's spouse, except where another rule, like the Dead Man's Statute, expressly says otherwise.
Full Text of CPLR 4512
Plain-English Summary
CPLR 4512 states a modern default: interest in the case is not, by itself, a reason to keep someone off the witness stand. A person is not excluded or excused from testifying merely because he has a stake in how the case comes out, is a party, or is married to a party. That default reverses the old common-law rule that treated an interested witness, or a party, as incompetent to testify at all.
The opening phrase, except as otherwise expressly prescribed, is doing real work. It flags that other sections still carve out exceptions to this general competency rule, most notably CPLR 4519, the Dead Man's Statute, which disqualifies certain interested witnesses from testifying about transactions with a person who has since died or become mentally incapacitated. CPLR 4502's limits on spousal testimony in adultery cases are another example.
Frequently Asked Questions
Can a party to a lawsuit testify in New York?
Yes. CPLR 4512 provides that a person is not excluded from being a witness merely because he is a party or has an interest in how the case comes out.
Can a spouse testify for or against their husband or wife in a civil case?
Does having a financial stake in a case make someone incompetent to testify?
No, not under CPLR 4512. Financial interest in the outcome goes to the weight and credibility of the testimony, not whether the person may testify at all.
What is the exception referenced in CPLR 4512?
The clause except as otherwise expressly prescribed points to statutes like CPLR 4519, the Dead Man's Statute, which still disqualifies certain interested witnesses in specific circumstances.
What rule did CPLR 4512 replace?
Former Civil Practice Act section 346, which similarly removed interest and party status as automatic grounds for disqualifying a witness.
Advisory Committee Notes
This section is a simplified form of former § 346. The words in the former section “except as otherwise specially prescribed” are not needed in view of the substitution of § 4519 for former § 347. The words of the former section “or of a person in whose behalf an action or special proceeding is brought, prosecuted, opposed or defended” are encompassed in the more general phrase “by reason of his interest in the event.” The opening phrase of this section alerts practitioners to the limitations contained in § 4502 relating to the testimony of a spouse.
Amendment History
Add, L 1962, ch 308, 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: competency of interested witness New Yorkcan a party testify in their own case New Yorkspouse competency to testify CPLR