Enforcing a Prenup or Postnup in a Florida Divorce (Including Agreements Signed in Another State or Country)

By Nadia Pazos, Family Law Attorney, Pazos Law Group · Updated October 7, 2026

You signed a prenuptial or postnuptial agreement years ago, and now a Florida divorce is starting. This page explains what happens to that agreement in the divorce: who has to prove what, what the agreement can and cannot control, and how a Florida court treats agreements signed in New York, another state, or another country.

Quick Answer

Will a Florida court enforce my prenup in a divorce?

Usually, yes. A signed, written premarital agreement is enforceable under Fla. Stat. § 61.079(3), and the spouse who wants out carries the burden: under § 61.079(7)(a) that spouse must prove the agreement was not signed voluntarily, was the product of fraud, duress, coercion, or overreaching, or was unconscionable when signed and all three disclosure failures listed in § 61.079(7)(a)3. occurred. A postnuptial agreement is judged under Casto v. Casto, 508 So. 2d 330 (Fla. 1987), not the statute. No agreement can adversely affect a child’s right to support (§ 61.079(4)(b)). Agreements made elsewhere are generally respected, but not where that would offend Florida public policy (Gustafson v. Jensen, 515 So. 2d 1298 (Fla. 3d DCA 1987)).

What Happens to a Prenup When a Florida Divorce Is Filed?

Nothing about the agreement changes because a case is filed. Under § 61.079(5), a premarital agreement “becomes effective upon marriage of the parties,” and § 61.079(1) says the section “applies only to proceedings under the Florida Family Law Rules of Procedure” — which is where a Florida divorce is decided. In practice, the spouse relying on the agreement raises it in the dissolution case, and the court applies it to the issues it covers: property, debts, and spousal support.

Time is less of a problem than people fear. Section 61.079(9) provides that any statute of limitations applicable to a claim for relief under a premarital agreement “is tolled during the marriage of the parties.” The same subsection keeps equitable defenses, including laches and estoppel, available to either party, so a spouse who acted for years as if the agreement applied may have a harder time arguing that it does not.

Who Has to Prove What?

If you are the spouse relying on the agreement

The statute’s formalities are minimal. Section 61.079(3) requires only that the agreement be “in writing and signed by both parties,” and it is “enforceable without consideration other than the marriage itself.” Section 61.079 itself contains no notary or witness requirement, and it does not require that either party had a lawyer. What matters is that you can produce the complete signed agreement with every schedule and exhibit, and any written amendment signed by both spouses after the wedding (§ 61.079(6)).

If you are the spouse challenging it

Section 61.079(7)(a) puts the burden on “the party against whom enforcement is sought.” The grounds are a closed list:

Not voluntary — § 61.079(7)(a)1.
Fraud, duress, coercion, or overreaching — § 61.079(7)(a)2.
Unconscionable when signed, plus all three disclosure failures — no fair and reasonable disclosure, no voluntary and express written waiver of further disclosure, and no adequate knowledge of the other spouse’s property or obligations (§ 61.079(7)(a)3.a.–c.).

Whether an agreement is unconscionable is decided by the judge as a matter of law (§ 61.079(7)(c)). For each ground in detail, see Can I Get Out of a Prenup I Signed in Florida?

What the Agreement Cannot Control in the Divorce

Child support. § 61.079(4)(b): “The right of a child to support may not be adversely affected by a premarital agreement.” Support is set under the guidelines in § 61.30.
Parenting and time-sharing. These are decided under § 61.13 on the child’s best interests when the issue arises; parents cannot bind the court in advance.
A spouse left on public assistance. If an alimony waiver would make one spouse eligible for public assistance at separation or dissolution, § 61.079(7)(b) lets the court require support “to the extent necessary to avoid that eligibility” — a floor, not a full alimony award.

What If It Is a Postnuptial Agreement?

Section 61.079 applies only to agreements made “in contemplation of marriage and to be effective upon marriage” (§ 61.079(2)(a)). An agreement signed after the wedding is governed by Florida case law, principally Casto v. Casto, 508 So. 2d 330 (Fla. 1987). Under Casto, a spouse can challenge a marital agreement on either of two grounds:

fraud, deceit, duress, coercion, misrepresentation, or overreaching; or
the agreement is unfair or unreasonable given the parties’ circumstances — which raises a presumption of concealment and shifts the burden to the spouse defending it to show full and fair disclosure, or that the challenging spouse had a general knowledge of the marital property.

That burden shift is why the disclosure exchanged when a postnup was signed often decides the case. More on postnups: Florida Postnuptial Agreement Attorney.

A Prenup Signed in New York or Another State

A prenup validly made under another state’s law is a contract, and Florida courts routinely give effect to contracts validly made under sister-state law. Many of these agreements select their own governing law — the same device Florida authorizes in § 61.079(4)(a)7., “the choice of law governing the construction of the agreement” — and a Florida court will ordinarily honor a reasonable choice of another state’s law for construing the agreement. Two practical points:

The divorce itself is still a Florida proceeding. Florida procedure applies, and Florida’s rules on child support and time-sharing apply regardless of the agreement.
Read the clause you actually have. A clause choosing New York law for construction is not the same as a clause choosing New York courts. What it covers matters.

An Agreement or Property Regime From Another Country

Florida analyzes foreign agreements and marital-property elections through comity: courtesy to the laws of other jurisdictions, extended unless doing so would offend Florida public policy. In Gustafson v. Jensen, 515 So. 2d 1298 (Fla. 3d DCA 1987), the Third District declined to give effect to a Danish separate-property arrangement where the fairness and disclosure Florida requires were not shown. A one-line separation-of-property election in a marriage record, with no disclosure and no counsel, is the profile that case warns about.

For a foreign agreement, the court will want the original or a certified copy, a certified English translation, and proof of how it was executed. Country-specific notes (Italy, Colombia, Brazil, Spain and others) are on our international prenup page.

Divorce Rights and Death Rights Are Separate

This page is about divorce. Waivers of a surviving spouse’s rights — elective share, homestead, exempt property — are governed by § 732.702, and § 61.079(10) confirms the premarital agreement statute does not alter those formalities. An agreement can be enforceable in a divorce and still be tested separately if a spouse dies.

What to Bring to a First Consultation

The complete signed agreement, with every schedule, exhibit, and financial disclosure attached when it was signed.
Any amendment, restatement, or revocation signed after the wedding (§ 61.079(6)).
The dates it was first sent, signed, and the wedding date, and whether each side had a lawyer.
For a foreign agreement: a certified copy, a certified English translation, and the marriage record if a property regime was elected there.
A short list of what has changed since: homes, businesses, accounts, children, and where you have lived.

Frequently Asked Questions

Do I have to prove my prenup is fair to enforce it in a Florida divorce?

No. Under Fla. Stat. § 61.079(7)(a), the spouse resisting the agreement must prove one of the statutory grounds. The spouse relying on it needs the complete written agreement signed by both parties (§ 61.079(3)).

Our prenup is from 2008 and says New York law applies. Can it be used in a Florida divorce?

Generally, yes. Florida courts give effect to contracts validly made under another state’s law, and a Florida court will ordinarily honor a reasonable choice-of-law clause for construing the agreement, as § 61.079(4)(a)7. allows. The divorce is still decided under Florida procedure, and child support and time-sharing are still decided under Florida law.

Is it too late to rely on, or challenge, a prenup signed many years ago?

Section 61.079(9) tolls any applicable statute of limitations during the marriage, but it also keeps laches and estoppel available to either party. Long delay, or years of acting as though the agreement applied, can matter.

Can a prenup or postnup decide child support or custody?

No. A premarital agreement cannot adversely affect a child’s right to support (§ 61.079(4)(b)); support follows the § 61.30 guidelines, and time-sharing is decided under § 61.13 on the child’s best interests.

We elected separation of property when we married abroad. Does that count as a prenup in Florida?

It may be treated as a marital-property agreement and considered through comity, but Florida does not give effect to foreign arrangements that offend its public policy, including where the disclosure and fairness Florida requires were not shown (Gustafson v. Jensen, 515 So. 2d 1298 (Fla. 3d DCA 1987)). Bring a certified copy and a certified translation.

Who decides whether the agreement is unconscionable?

The judge. Fla. Stat. § 61.079(7)(c) provides that unconscionability is decided by the court as a matter of law.

Official Sources & Related Reading

The information on this page is for general informational purposes only and does not constitute legal advice. Reading or sharing this content does not create an attorney-client relationship with Pazos Law Group. Florida law and the application of statutes change over time; please consult a licensed Florida attorney about your specific situation.