Florida Divorce Prenuptial Agreement Enforcement: When a Prenup Holds and When It Fails

Prenuptial Agreements Are Presumed Valid

Florida adopted the Uniform Premarital Agreement Act (UPAA) under Florida Statute § 61.079. A prenup must be in writing and signed by both parties. Courts generally enforce a properly executed agreement unless a statutory challenge is proved.

A prenup can govern almost every financial aspect of a divorce: which assets remain nonmarital, how marital assets are divided, whether alimony is available (and in what amount), and how debts are allocated. The one thing a prenup cannot do is determine child custody or child support — those are governed by the best interests of the child and statutory guidelines, and courts will not enforce private agreements that override them.

The Statutory Grounds for a Challenge

A spouse challenging a prenup must establish one of these statutory grounds:

Involuntariness, Fraud, Duress, or Overreaching

The challenging spouse must prove they did not sign the agreement voluntarily or that it was the product of fraud, duress, coercion, or overreaching. Florida courts look at the totality of the circumstances: was there adequate time to review the agreement before signing? Did the challenging spouse have access to independent legal counsel? Was there coercion, duress, or undue pressure (presenting the agreement the night before the wedding, for example)?

Having independent legal counsel is not required, but a spouse who had their own attorney review the agreement will have a much harder time claiming involuntariness. Conversely, an agreement presented for the first time at the rehearsal dinner — with the implicit threat that the wedding will be canceled — is vulnerable to an involuntariness challenge.

Unconscionability and Financial Disclosure at Execution

The agreement must not have been unconscionable when it was signed. Unconscionability is a high bar in Florida — it requires the agreement to be so one-sided that no reasonable person would have agreed to it, and that the resulting terms shock the conscience of the court. The statutory disclosure challenge also requires the additional conditions described below.

An agreement where one spouse waives all rights to property division and alimony is not automatically unconscionable. But an agreement that leaves one spouse destitute while the other retains millions, combined with circumstances suggesting the disadvantaged spouse did not understand what they were giving up, may cross the line.

What the Disclosure Challenge Requires

Under the UPAA, inadequate disclosure alone is not enough. The challenging spouse must show that the prenup was unconscionable when signed and that, before signing, they were not provided fair and reasonable disclosure, did not voluntarily waive disclosure in writing, and did not have (or reasonably could not have had) adequate knowledge of the other party's property and financial obligations.

The disclosure does not need to be exact to the dollar, but it must be materially complete. Omitting a significant asset — a business interest, a trust fund, a real estate portfolio — can make the agreement vulnerable when the other statutory conditions are also met.

Alimony Waiver That Creates Public-Assistance Eligibility

Even if a prenup is otherwise valid, a court can refuse to enforce an alimony waiver if doing so would cause one spouse to be eligible for support under a public-assistance program at separation or dissolution. This is a narrow exception — the court does not simply recalculate alimony because the waiver seems unfair.

Postnuptial Agreements in Florida

Postnuptial agreements (signed during the marriage) are enforceable in Florida but are held to a higher standard than prenuptial agreements. Because the spouses are already in a fiduciary relationship, courts scrutinize postnuptial agreements more carefully for fairness and adequate disclosure.

The same basic requirements apply: voluntariness, adequate disclosure, and a written agreement signed by both parties. But courts are more willing to find unconscionability in a postnuptial context because the power dynamics of an existing marriage — financial dependence, emotional pressure, fear of divorce — create greater opportunity for overreach.

A postnuptial agreement is commonly used to address a specific event: one spouse receives a large inheritance and wants to preserve its nonmarital character, or the couple reconciles after a separation and wants to restructure their financial arrangements going forward.

What This Means for Your Divorce

If your divorce involves a prenuptial or postnuptial agreement, the first step is determining whether the agreement will survive a challenge. Examine:

• Was full financial disclosure provided? Look for a schedule of assets and liabilities attached to or referenced in the agreement. If it is missing or materially incomplete, the agreement may be vulnerable when the statutory challenge conditions are also met.
• Did both spouses have independent counsel? If one spouse had an attorney draft the agreement and the other signed without legal representation, the voluntariness question becomes more contested.
• How far apart were the signing date and the wedding date? Agreements signed weeks or months before the wedding are much stronger than those signed days before.
• Does the agreement address all current issues? A prenup from a first marriage that does not contemplate retirement accounts, stock options, or a business started during the marriage may leave significant gaps that the court fills under standard equitable distribution rules.

The Florida Divorce Financial Split Guide includes an equitable distribution worksheet that accounts for prenuptial and postnuptial agreement terms — classifying assets according to the agreement's terms rather than default statutory rules, and flagging where gaps in the agreement leave assets subject to standard division.

See more Florida guides →