Are Prenuptial Agreements Enforceable in New York?

A prenuptial agreement (also called a premarital agreement or "prenup") is a written contract entered into by two people before they marry. It typically addresses what will happen to property and finances if the marriage ends in divorce, separation, or death. Prenups can also be entered into during marriage — in that case they are called postnuptial agreements and are subject to slightly different rules.

Under New York Domestic Relations Law § 236(B)(3), prenuptial agreements can address:

• Which property remains separate and which becomes marital
• How property will be divided in the event of divorce
• Spousal maintenance (amount, duration, or waiver)
• Rights to specific assets (a family business, an inheritance, a home)
• Financial responsibilities during the marriage
• Estate planning and inheritance rights

Certain matters are off-limits for prenuptial agreements in New York:

• Child custody and child support. Courts will not enforce prenup provisions that predetermine custody arrangements or waive child support. The child's best interests must be determined at the time of divorce, not in advance.
• Anything illegal or against public policy. A prenup cannot encourage divorce, include unconscionable terms, or waive rights in ways that violate law.

For a prenuptial agreement to be enforceable in New York, it must meet specific formal requirements:

• Written and signed. Oral prenuptial agreements are not enforceable.
• Acknowledged before a notary. New York requires prenups to be acknowledged in the same manner as a deed — before a notary public. This is a technical but critical requirement.
• Voluntary. Both parties must have signed freely, without duress or coercion.
• Full financial disclosure. Both parties should fully disclose their assets and liabilities. Concealment of significant assets can invalidate a prenup.
• Independent legal counsel. While not legally required, courts look more favorably on prenups where both parties had their own attorneys.

New York courts will refuse to enforce a prenup that:

• Was signed under duress (e.g., presented the night before the wedding with pressure to sign)
• Was procured by fraud or misrepresentation
• Did not comply with acknowledgment formalities
• Was unconscionable at the time of signing — so one-sided as to shock the conscience

Note: The fact that a prenup turns out to be financially unfavorable does not by itself make it unenforceable. Courts respect the right of informed adults to make their own financial arrangements.

A postnuptial agreement is the same kind of contract as a prenup — just signed after the wedding. New York recognizes them under the same statute, and the same formalities apply: written, signed, acknowledged before a notary in the form required for a deed, voluntary, with full financial disclosure.

The most common reasons couples sign a postnup in our practice:

• One spouse is about to start, inherit, or take over a closely-held business and wants to clarify how that asset will be treated.
• The couple worked through a serious marital problem and wants the financial terms of any future divorce settled while they are still on speaking terms.
• An existing prenup has become outdated — new children, a major career change, or a substantial inheritance has shifted the picture.

An existing prenup can also be amended after marriage. The amendment itself must satisfy the same execution formalities as the original prenup — signing a one-page modification on the kitchen table will not bind anyone. If you have a prenup and your circumstances have changed materially, talk to a family law attorney about whether a formal amendment or a postnuptial agreement is the better tool.

One caution: courts apply slightly heightened scrutiny to postnups, because the leverage dynamic during a marriage can be different from the leverage dynamic before one. Independent counsel for both spouses and contemporaneous financial disclosure are even more important after the wedding than before it.

If you are asked to sign a prenup, give yourself time to review it, consult your own attorney, and negotiate any terms that concern you. If you are the one proposing a prenup, present it well in advance of the wedding, ensure full disclosure, and encourage your partner to seek independent legal advice — all of which strengthen enforceability.

If you believe a prenup you signed is invalid or should not be enforced, an experienced attorney can evaluate the circumstances of its execution and advise you on your options.

Weinrieb Law drafts, reviews, and challenges prenuptial agreements for clients throughout Western New York. Whether you are planning ahead or facing a divorce where a prenup is at issue, we can help.