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Litigation. Collaborative Law. Mediation.

Can You Challenge a Prenuptial or Postnuptial Agreement?


Prenuptial and postnuptial agreements are valuable tools for protecting wealth and other assets, and offer couples a way to safeguard against the unexpected. Both parties must enter into the agreements honestly, committing to full and frank disclosure when it comes to their needs and their goals. Like any legal contract, however, prenuptial and postnuptial agreements can be challenged under certain circumstances:

  1. Fraud
  2. Duress (potentially including “undue influence”)
  3. Unconscionability

We will discuss all three of these challenges, but it is also worth noting that the spouse challenging a prenuptial agreement or postnuptial agreement, or any given clause or provision of the agreement, must establish the existence of some kind of impropriety in the creation of the agreement. Divorce courts in New York established and upheld a rule on this matter in Rabinovich v. Shevchenko, 93 AD3d 774 and Christian v. Christian, 42 NY2d 63.


In the creation of a prenuptial or postnuptial agreement, both parties must honestly disclose any debts and assets they have. Those debts and assets must be valued correctly, and they must be presented during discovery. If, for example, one party intentionally hid assets, or purposely devalued assets or debts during the creation of the agreement, the agreement could be invalidated as being fraudulent.


If one party was forced or coerced into signing a prenuptial or postnuptial agreement, the court may rule it inadmissible. If, for example, Spouse A presents a prenuptial agreement to Spouse B on the eve of their wedding, Spouse B may feel obligated to sign it, even if Spouse B has not reviewed the agreement in full nor had time to speak with an attorney about it.

That being said, proving duress can be difficult: Elizabeth Petrakis spent seven years proving she was under duress when she signed her prenuptial agreement right before her wedding. She was, however, eventually successful in having it invalidated.

New York courts strongly favor allowing prenups to stand, even in cases that may seem egregious to non-attorneys. For example, even these “night before the wedding” cases usually require some kind of additional unfairness – it is in fact legal to spring a prenup on your partner just before the wedding! However, if the prenup was a last-minute surprise, and is egregiously one-sided, that may be enough to void it.


To be blunt, prenuptial and postnuptial agreements should not be egregiously lopsided. This potential issue should be addressed during the drafting process. An extremely unfair prenup could be considered “unconscionable” by a court. In McKenna v. McKenna, 121 A.D.3d 864 (2014), the decision defined an unconscionable agreement as one in “which no person in his or her senses and not under delusion would make on the one hand, and no honest and fair person would accept on the other, the inequality being so strong and manifest as to shock the conscience and confound the judgment of any person of common sense.”

In other words, a prenuptial agreement that is grossly unfair, or contains ridiculous provisions, can be invalidated even if both parties agreed to the provisions. It can also be invalidated if circumstances change so significantly over time that what was once an equitable agreement ends up becoming unconscionable by the end of the marriage: see, for example, Taha v Elzemity, 2018.

Prenuptial agreements must also be executed exactly according to statutory mandates. Signatures alone are insufficient, and must be witnessed by a notary. Prenuptial agreements can be overturned if they fail to adhere to New York’s stringent formalities concerning execution and notarization.

Case law forbids any single factor alone to invalidate a prenuptial agreement. A number of factors must be present to establish the invalidity of the agreement, and most notably, there must be elements of both procedural (the signing) and substantive (the content) unfairness. An experienced divorce attorney can help you make this determination.

The NYC divorce attorneys at Berkman Bottger Newman & Schein LLP offer meticulous, effective counsel for all family law matters. To arrange a consultation regarding a prenuptial or postnuptial agreement, please call (212) 466-6015 or fill out our contact form. We serve clients in and around New York City, Westchester, and Bergen County, NJ.