What Makes a Prenup Invalid in Florida?

You signed a prenuptial agreement before the wedding. Now you’re facing divorce, and the terms of that agreement could determine how your assets get divided. But what if the prenup wasn’t done properly?

An invalid prenup in Florida can be thrown out entirely, which changes everything about your property division.

Florida has specific legal requirements for prenuptial agreements. If yours doesn’t meet them, you may have grounds to challenge it.

Florida’s Legal Framework for Prenuptial Agreements

Florida adopted the Uniform Premarital Agreement Act, codified under Florida Statute § 61.079. This statute governs all prenuptial agreements signed on or after October 1, 2007.

A valid prenup must meet three basic requirements:

• It must be in writing
• It must be signed by both parties
• It must be executed voluntarily

No additional consideration beyond the marriage itself is required. But meeting these minimum requirements is just the starting point.

The real battles over an invalid prenup in Florida usually come down to voluntariness, disclosure, and unconscionability.

The Prenup Was Not Signed Voluntarily

This is the most common basis for challenging a prenup. Voluntariness doesn’t just mean nobody held a gun to your head. Courts look at the totality of the circumstances surrounding the signing.

Factors that suggest a prenup was involuntary:

• Presented at the last minute. If your spouse handed you the prenup days or hours before the wedding, with guests arriving and deposits paid, courts may find you didn’t have meaningful time to consider the terms.
• No independent legal counsel. While Florida doesn’t require both parties to have their own attorney, the absence of independent legal advice is a significant factor. If one spouse had an attorney draft the agreement and the other signed without counsel, that imbalance weighs against enforceability.
• Duress or coercion. Threats to cancel the wedding, withdraw financial support, or end the relationship unless the agreement was signed can constitute duress.
• Fraud or misrepresentation. If one party lied about the terms, misrepresented their meaning, or concealed material information to induce signing, the agreement can be voided.

Inadequate Financial Disclosure

Under § 61.079, a party challenging a prenup on unconscionability grounds must show that they were not provided fair and reasonable disclosure of the other party’s property and financial obligations.

What constitutes adequate disclosure:

• Complete asset inventory. Both parties should have provided a full accounting of their assets, including bank accounts, investments, real estate, business interests, and retirement accounts.
• Debt disclosure. All liabilities must be disclosed. Signing a prenup without knowing your spouse carried $500,000 in business debt changes the equation entirely.
• Income and earning capacity. Both parties should understand each other’s current income and future earning potential.

There is an exception: a party can voluntarily and expressly waive the right to disclosure in writing.

But even a waiver can be challenged if the court finds it wasn’t truly voluntary or if the party didn’t have and reasonably couldn’t have had adequate knowledge of the other spouse’s finances.

The Agreement Is Unconscionable

Unconscionability means the terms are so one-sided that enforcing the agreement would be fundamentally unfair.

Florida courts analyze this at the time the agreement was signed, not at the time of divorce.

Courts apply a two-part test:

1. Substantive unconscionability

The actual terms of the agreement are grossly unfair. For example, one spouse waives all rights to property division and alimony regardless of circumstances while the other retains everything.

1. Procedural unconscionability

The process of creating and signing the agreement was fundamentally unfair. This overlaps with voluntariness and disclosure issues.

A prenup doesn’t have to be perfectly equal to be enforceable. Courts recognize that the entire point of a prenup is to alter what would otherwise happen under equitable distribution.

But when the terms are so extreme that no reasonable person would agree to them with full information, the agreement may not survive a challenge.

Technical Defects That Can Invalidate a Prenup

Beyond the substantive grounds, technical problems can render a prenup unenforceable:

• Not in writing. Oral prenuptial agreements are not enforceable in Florida.
• Missing signatures. Both parties must sign the agreement.
• Provisions that violate public policy. A prenup cannot determine child custody or child support. Any provisions attempting to do so are void, though the rest of the agreement may remain enforceable.
• Provisions encouraging divorce. Terms that create financial incentives for one spouse to file for divorce may be struck down.

What About Prenups Signed Before October 1, 2007?

The UPAA only applies to prenuptial agreements executed on or after October 1, 2007.

If your prenup was signed before that date, Florida common law governs its enforceability instead.

Under the pre-UPAA standard, courts apply a different analysis:

• The agreement must have been made with full and fair disclosure of each party’s assets and financial obligations at the time of signing.
• The agreement must not have been obtained through fraud, duress, coercion, or overreaching.
• The terms cannot be unconscionable when measured against the circumstances at the time of enforcement, not just at the time of signing. This is a key difference from the UPAA, which only evaluates unconscionability at the time of execution.

If you signed a prenup before 2007, the enforceability analysis may actually work in your favor or against you, depending on how circumstances have changed since signing.

Who Has the Burden of Proof?

The party challenging the prenup bears the burden of proving it should not be enforced.

Under § 61.079, this means demonstrating that the agreement was involuntary, or that the terms are unconscionable, and that adequate financial disclosure was not provided.

What Happens If a Prenup Is Found Invalid?

If the court invalidates your prenup, your divorce proceeds as if the agreement never existed. All assets and liabilities are subject to equitable distribution under Florida Statute § 61.075.

This means:

• All marital assets are subject to division
• Alimony becomes available based on statutory factors
• The court applies the full equitable distribution analysis rather than the prenup’s terms

Courts can also invalidate specific provisions while enforcing the rest of the agreement. The outcome depends on how the agreement was drafted and which provisions are challenged.

Challenging or Defending a Prenup in Your Florida Divorce

Whether you’re trying to enforce a prenup or challenge one, the facts surrounding how the agreement was created and signed matter as much as the terms themselves. Timing, disclosure, legal representation, and the fairness of the terms all play a role.

Nest Law represents clients on both sides of prenuptial agreement disputes in Florida divorces. If you have questions about whether your prenup will hold up or how to challenge one, we can evaluate your situation.

Contact Nest Law to schedule a confidential consultation.