The execution requirements are strict
Under DRL §236(B)(3), a marital agreement must be:
- In writing
- Signed by both parties
- Acknowledged in the manner required to record a deed
That third requirement is where agreements die. An acknowledgment is a formal step in front of a notary, and it is not satisfied by a signature that merely happens to be witnessed. New York courts have voided agreements — including long-standing ones relied on for years — for defective acknowledgment, regardless of how clearly both parties intended to be bound.
Galetta v Galetta and Anderson v Anderson confirm the formal acknowledgment requirement. Anderson allows limited proof that a timely, proper acknowledgment actually occurred when its certificate was defective; it does not permit a party simply to supply a missing acknowledgment years later.
What an agreement can cover
- How property is divided, including whether assets acquired during the marriage stay separate
- Whether spousal maintenance is paid, and how much, or is waived entirely
- Treatment of a business, a professional practice, or an inheritance
- Responsibility for debt
- What happens to specific assets, including a home or a companion animal
What it cannot cover
Child custody. A court decides custody on the best interests of the child at the time, and parents cannot contract that away in advance.
Child support. Support belongs to the child rather than the parents. A waiver or a below-guideline figure agreed in advance is not binding on a court.
Agreements sometimes include provisions on these anyway. They do not bind the court.
Why agreements get set aside
- Defective acknowledgment, as above — the most common technical failure
- Lack of financial disclosure. An agreement signed without knowing what the other party has is vulnerable.
- Duress. The agreement presented days before the wedding, with guests arriving, is the classic fact pattern.
- Unconscionability, where the terms are so one-sided the court will not enforce them.
- No independent counsel. Not strictly required, but an agreement where one party had a lawyer and the other did not is easier to attack.
The practical lesson: negotiate early, disclose fully, and have both parties separately represented. An agreement that is cheap to produce and easy to void is worth nothing at exactly the moment it is needed.
Frequently asked questions
Are prenuptial agreements enforceable in New York?
Yes, where properly executed. They must be in writing, signed, and acknowledged with the formality required to record a deed. Acknowledgment defects can make an agreement unenforceable, subject to the limited rule permitting proof of timely compliance.
Can a prenup decide child custody or child support?
No. Custody is decided on the child’s best interests at the time, and child support belongs to the child. Neither can be contracted away in advance.
What is a postnuptial agreement?
The same kind of agreement, made during the marriage rather than before it. Common after a business is started or an inheritance is received.
Do we both need lawyers?
Not strictly required, but strongly advisable. An agreement where only one party had counsel is easier to challenge.
Can a prenup be thrown out?
Yes — for defective execution, inadequate financial disclosure, duress, or unconscionable terms. Careful drafting and early negotiation are what make one hold.
Related: Divorce · Equitable Distribution · Care Agreements · back to Family Law
Written by Dale Riedel, Esq. · Admitted in New York, Bar No. 5837539 · Last reviewed October 6, 2026