Postnuptial Agreements in New York

A postnuptial agreement is a contract between spouses who are already married, setting out how property, debt and support would be handled if the marriage ended. New York expressly permits them — the Domestic Relations Law allows agreements made “before or during the marriage” — but it holds them to formal requirements that are unforgiving, and it examines them more closely than it examines prenuptial agreements. Getting one right matters considerably more than getting one signed.

Why couples make one

Postnuptial agreements are rarely about expecting a divorce. In practice they tend to arise at specific moments.

One spouse starts a business and the other wants clarity that the household is not exposed to its debts. An inheritance arrives and the couple want it treated as separate property beyond argument. One spouse leaves work to raise children and wants that sacrifice reflected in writing rather than in assumptions. A couple reconciles after a serious difficulty and wants the terms of continuing settled. Or a couple simply married without a prenuptial agreement and later wish they had.

What they share is a preference for deciding terms while both people are still cooperating, rather than leaving them to be litigated later.

The formal requirements — and why agreements fail them

New York law requires that the agreement be in writing, subscribed by both parties, and acknowledged or proven in the manner required to entitle a deed to be recorded.

That last requirement causes more invalid agreements than every other issue combined. It is not enough that both spouses signed, that both intended to be bound, or that neither disputes signing. The acknowledgment — the formal notarial certificate in proper form — must be there and must be correct. New York courts have refused to enforce agreements for defective acknowledgment even where nobody questioned that the signatures were genuine.

The consequence is stark: a couple can negotiate carefully, sign in good faith, rely on the agreement for years, and discover at the point it matters that it was never enforceable. This is the single strongest reason not to use a template.

What a postnuptial agreement can cover

The statute permits a broad range of terms. An agreement can set out how separate and marital property will be owned, divided or distributed — which is the core of most postnups and directly shapes what would otherwise be decided under equitable distribution.

It can fix the amount and duration of maintenance, subject to statutory conditions about fairness. It can contain a contract to make a testamentary provision, or a waiver of the right to elect against a will — which is why postnups often sit alongside estate planning. It can address debt, business interests, and the treatment of property acquired during the marriage.

What it cannot decide

Agreements about children occupy a different position. Provisions about custody, care, education and maintenance of a child are permitted, but they remain subject to the court’s own statutory obligations.

A court will not treat a parental agreement as binding where it conflicts with a child’s best interests, and it will not enforce a waiver of child support that leaves a child inadequately provided for. You can record what you have agreed; you cannot contract away the court’s role.

How a postnup differs from a prenup

The formal requirements are the same, and the same statute governs both. The practical difference is the degree of scrutiny.

People negotiating a prenuptial agreement are, in law’s view, still at arm’s length. Married spouses are not — they stand in a relationship of trust and confidence, which means a postnuptial agreement receives closer examination for fairness, for full disclosure, and for whether one spouse took advantage of the other’s position.

The lopsided postnup is therefore more vulnerable than the lopsided prenup. An agreement in which one spouse waives nearly everything invites the question of what was really happening at the time it was signed.

How postnuptial agreements are challenged

When a marriage ends, a spouse unhappy with the agreement will look for a way out. The arguments are predictable, which is useful, because it means they can be anticipated.

Defective execution is the first and most effective. Non-disclosure is the second — an agreement signed without a full picture of the other spouse’s assets is exposed. Duress and overreaching come next, and the classic version is an agreement produced with an ultimatum attached and little time to consider it. Unconscionability is available where the terms are so one-sided as to shock the conscience. And the absence of independent legal advice, while not fatal by itself, weakens every defence to all of the above.

What makes one hold up

Agreements that survive tend to share the same features. Both spouses had their own lawyer. Both made full written disclosure of assets, income and debts, attached to the agreement itself. There was real time between the first draft and the signing. The terms, even if favourable to one side, are explicable — and the reasoning is recorded. And the execution formalities were completed exactly as the statute requires.

None of that is expensive relative to litigating the agreement’s validity later, which is the alternative.

Common questions about postnuptial agreements

Can we make one if we are already having problems?

Yes, and many are made in exactly that situation. Be aware that the circumstances of signing will be examined if the agreement is later challenged, which makes independent advice for both spouses more important, not less.

Do we both need our own lawyer?

It is not strictly required, but one lawyer cannot represent both spouses in negotiating an agreement between them. An agreement where only one side had advice is materially easier to attack.

Can we change or cancel it later?

Yes, by a further written agreement executed with the same formalities. An informal understanding to disregard it will not do.

Does a postnup mean we are heading for divorce?

No. Most are made by couples intending to stay married who prefer certainty to ambiguity, particularly where a business, an inheritance or a career sacrifice is involved.

Will it be enforced if we divorce in another state?

Usually, though enforcement depends on the law of the state where the divorce takes place. This is worth raising if you expect to move.

What if my spouse hid assets when we signed?

Non-disclosure is one of the strongest grounds for setting an agreement aside. Bring what you have to a consultation.

Speak with a Queens family lawyer

Whether you are considering a postnuptial agreement or questioning one you have already signed, the formalities and the circumstances of signing usually decide the outcome. Call (718) 206-1555 to discuss it, or read more about our divorce and family law practice.