Can a Prenup Be Thrown Out in Florida? (2026 Guide)

A prenup can be thrown out in Florida if the challenging spouse proves the agreement was signed involuntarily, was the product of fraud, duress, coercion, or overreaching, or was unconscionable when executed under Fla. Stat. § 61.079. The challenger carries the burden of proof, and unconscionability also requires inadequate financial disclosure.

Florida enforces most prenuptial agreements, but a properly raised challenge succeeds in a meaningful minority of contested cases. The Uniform Premarital Agreement Act (UPAA), codified at Fla. Stat. § 61.079 in 2007, combined with the Florida Supreme Court's framework in Casto v. Casto, 508 So. 2d 330 (Fla. 1987), governs when an invalid prenup gets set aside. This guide explains every ground for challenging a prenup, the evidence courts demand, and the leading cases where agreements were invalidated.

Key Facts: Florida Divorce and Prenups

Filing fees are as of March 2026. Verify with your local clerk before filing.

Can a Prenup Be Thrown Out in Florida?

Yes, a prenup can be thrown out in Florida under three statutory grounds in Fla. Stat. § 61.079(7): the agreement was not executed voluntarily; it was the product of fraud, duress, coercion, or overreaching; or it was unconscionable when executed combined with inadequate financial disclosure. The spouse challenging the agreement carries the burden of proof.

Florida courts start from a presumption that a signed, written prenup is valid and enforceable. Under Fla. Stat. § 61.079(4), a premarital agreement must be in writing and signed by both parties, and it is enforceable without consideration other than the marriage itself. Oral prenups are never enforceable in Florida. The challenger must overcome the validity presumption with specific evidence, not general claims of unfairness. A bare assertion that the deal was lopsided will not invalidate it, because Florida permits parties to make unequal bargains. The challenger must connect the unfair terms to a recognized defect such as concealed assets, coercive timing, or an absence of meaningful choice at signing. Roughly 90 percent of properly drafted Florida prenups withstand challenge, which is why the quality of the original drafting and disclosure process matters more than the fairness of the final split.

Ground 1: Involuntary Execution

A prenup is thrown out for involuntary execution when the challenging spouse proves they did not sign the agreement of their own free will, as required by Fla. Stat. § 61.079(7)(a)1. Courts examine the totality of circumstances, including timing, access to independent counsel, and whether the signer understood the rights being waived. Voluntariness is judged at the moment of signing.

Voluntariness is the most common battleground in prenup litigation. Florida courts look at whether the disadvantaged spouse had a genuine opportunity to read, understand, and reject the agreement. Several recurring fact patterns push a court toward an involuntariness finding. Presenting the document on the eve of the wedding, when guests have arrived and deposits are paid, signals that the signer faced practical compulsion rather than free choice. Denying access to an independent attorney, or actively discouraging review, weighs heavily against the drafting spouse. A signer who cannot read English fluently, who was given no translation, or who was kept unaware of what rights were being surrendered may establish involuntariness. The presence of independent counsel for each party is not legally required in Florida, but it is one of the strongest pieces of evidence that signing was voluntary, which is why careful drafters insist on it.

Ground 2: Fraud, Duress, Coercion, or Overreaching

A prenup is invalidated for fraud, duress, coercion, or overreaching under Fla. Stat. § 61.079(7)(a)2 when one spouse used improper pressure or deception to obtain the other's signature. Fraud involves intentional misrepresentation or concealment; duress involves wrongful threats; overreaching involves exploiting a power imbalance to extract an unfair agreement.

These four related defects share a common theme: the agreement reflects one party's improper conduct rather than genuine mutual assent. Fraud typically appears as a deliberately false financial picture, such as hiding a business interest, understating income, or omitting major accounts so the other spouse cannot evaluate what they are giving up. Duress arises from wrongful threats, such as a threat to cancel the wedding hours before the ceremony unless the prenup is signed, leaving no realistic alternative. The landmark case Hjortaas v. McCabe, 656 So. 2d 168 (Fla. 2d DCA 1995), found duress where the husband presented the agreement just two days before the wedding with no financial disclosure, giving the wife no time to consult counsel or cancel. Overreaching describes a sophisticated party taking advantage of an unsophisticated one, often combined with a grossly one-sided result. In Baker v. Baker, the court invalidated an agreement as unconscionable and overreaching where a wife in her sixties waived $55,000 in annual alimony, equitable distribution, and estate rights.

Ground 3: Unconscionability Plus Inadequate Disclosure

A prenup is unconscionable and unenforceable under Fla. Stat. § 61.079(7)(a)2.b only when three conditions all exist: the agreement was unconscionable when signed; the challenging spouse was not given fair and reasonable disclosure of the other's property; and that spouse did not waive disclosure in writing and could not reasonably have known the other's finances. Unconscionability is decided by the judge as a matter of law.

Unconscionability is the hardest ground to win because Florida requires a stacked showing rather than mere unfairness. An agreement that leaves one spouse with almost nothing is not automatically unconscionable; Florida adults are free to strike bad bargains if they do so with open eyes. The unconscionability path only opens when the lopsided result is paired with a disclosure failure. Under Fla. Stat. § 61.079(7)(a)2, the challenger must prove all of the following: the terms were unconscionable at execution, no fair and reasonable disclosure of property and obligations was provided, the right to disclosure was not expressly waived in writing, and the challenger could not have had adequate knowledge of the other's finances through other means. The disclosure standard is not perfection. Florida courts hold that disclosure is satisfied when the challenging spouse possessed general and approximate knowledge of the other's property sufficient to make an intelligent decision. A schedule listing accounts and approximate values typically satisfies this requirement.

Burden of Proof and the Casto Framework

The burden of proving a prenup invalid rests entirely on the spouse challenging it, under both Fla. Stat. § 61.079(7) and Casto v. Casto, 508 So. 2d 330 (Fla. 1987). The challenger must prove fraud, duress, coercion, overreaching, or involuntary execution by competent evidence. For unconscionability, the challenger must additionally prove inadequate financial disclosure as a separate element.

The Florida Supreme Court's decision in Casto established the analytical structure that the UPAA later codified. Casto recognized two independent ways to challenge a marital agreement. First, a challenger may prove the agreement was reached through fraud, deceit, duress, coercion, misrepresentation, or overreaching. Second, a challenger may show that the agreement makes an unfair or unreasonable provision for the challenging spouse, given the circumstances, which then shifts a burden to the defending spouse to prove either full disclosure or that the challenger had adequate independent knowledge. The 2007 UPAA refined this framework and clarified that unconscionability is a question of law for the judge, not the jury. Practically, this means the challenger must build a detailed factual record at trial, because the validity presumption favors enforcement. Generalized complaints about fairness, without evidence tied to a statutory ground, routinely fail.

What a Prenup Cannot Control in Florida

A Florida prenup cannot waive or limit child support, cannot predetermine child custody or timesharing, and cannot eliminate spousal support if doing so leaves one spouse on public assistance, under Fla. Stat. § 61.079(8). Provisions attempting to control these areas are unenforceable even if the rest of the agreement is valid.

Florida law carves out protections that no prenup can override because they involve third-party or public interests. The right of a child to support may not be adversely affected by a premarital agreement; child support belongs to the child, not the spouses, and a court sets it under the statutory guidelines regardless of contract terms. Child custody and timesharing are decided by the best-interests standard in Fla. Stat. § 61.13 at the time of divorce, so prenup clauses dictating who gets the children carry no weight. Spousal support waivers are generally enforceable, but Fla. Stat. § 61.079(8) contains a public-assistance safety valve: if eliminating support would make one spouse eligible for public assistance at separation or dissolution, a court may order support despite the waiver. Importantly, a single unenforceable clause does not automatically void the entire agreement; courts often sever the invalid provision and enforce the remainder.

How to Challenge a Prenup During a Florida Divorce

To challenge a prenup in Florida, a spouse raises the agreement's invalidity in the dissolution proceeding, typically as an affirmative defense or counterclaim, then proves a statutory ground at an evidentiary hearing. The challenge must occur within the divorce case under Fla. Stat. § 61.079. Filing the divorce itself costs approximately $418 in court fees.

A prenup challenge unfolds inside the divorce action rather than as a separate lawsuit. The spouse seeking to set aside the agreement pleads the specific grounds, conducts discovery to obtain financial records and communications surrounding the signing, and presents evidence at a hearing. Key evidence includes the timeline between the agreement and the wedding, drafts and email exchanges, the financial disclosure schedules attached to the agreement, and testimony about whether independent counsel was available. Because unconscionability is decided as a matter of law, the judge rules on that issue based on the trial record. The statute of limitations is tolled during the marriage under Fla. Stat. § 61.079(11), so the clock does not run against a spouse while they remain married. After marriage, a prenup can be amended, revoked, or abandoned only by a later written agreement signed by both parties; informal or oral changes are ineffective.

Costs and Timeline of Contesting a Prenup

Contesting a prenup in a Florida divorce typically adds $5,000 to $25,000 or more in attorney fees and extends the case timeline by several months, on top of the base $418 filing fee. An uncontested Florida divorce can finalize after the 20-day waiting period under Fla. Stat. § 61.19, but a contested prenup fight usually takes 8 to 18 months.

The financial and time cost of challenging a prenup is significant because it converts an otherwise routine dissolution into contested litigation. The base court costs remain modest: approximately $408 for the dissolution filing plus $10 for the summons, totaling around $418 as of March 2026, with amounts set by Fla. Stat. § 28.241 and minor county variation. The real expense comes from discovery, expert valuations of concealed or disputed assets, and trial preparation. A simplified or uncontested divorce in Florida can cost as little as $500 to $1,500 total, while a contested case involving a prenup challenge commonly runs $10,000 to $25,000 or more per spouse. Spouses who cannot afford the filing fee may apply for an indigent-status waiver if household income falls below 200 percent of the federal poverty level, with the clerk typically reviewing applications within about five business days.

Cost ranges are estimates as of March 2026. Verify current court fees with your local clerk.