Missouri Prenup Guide

Missouri Prenup Laws: Requirements & Enforceability

Everything engaged couples need to know about making a prenuptial agreement valid and enforceable in Missouri — in plain English, reviewed by attorney James Sexton, Esq.

Start Your Missouri Prenup →Last reviewed: July 2026

Key takeaways

  • Prenups are legal and enforceable in Missouri, but the state never adopted the Uniform Premarital Agreement Act — case law controls.
  • Missouri's governing standard comes from Ferry v. Ferry, 586 S.W.2d 782 (Mo. App. 1979): the agreement must be entered 'freely, fairly, knowingly, understandingly, and in good faith with full disclosure.'
  • Missouri courts also require the agreement to be conscionable — a deal that is grossly one-sided can be set aside even if properly signed.
  • Judges weigh access to independent counsel, time to review, each party's bargaining position, and the quality of financial disclosure.
  • Missouri is an equitable-distribution state, so a prenup is how couples decide property division instead of leaving it to a judge.

Are prenups legal in Missouri?

Yes — prenuptial agreements are legal and enforceable in Missouri, governed by court-made case law rather than a statute.

Missouri is one of the minority of states that never adopted the Uniform Premarital Agreement Act. Instead, Missouri prenups are governed by common law, with the controlling standard set out in Ferry v. Ferry, 586 S.W.2d 782 (Mo. App. 1979): a premarital agreement is enforceable only if it was entered into freely, fairly, knowingly, understandingly, and in good faith with full disclosure. Later decisions such as McGilley v. McGilley (Mo. App. 1997) apply the same test and add a conscionability check, so a Missouri prenup must be both fairly made and fair in substance when signed.

What makes a prenup enforceable in Missouri?

A Missouri prenup is enforceable when it satisfies the Ferry v. Ferry test — signed freely and knowingly, with full financial disclosure, and conscionable in its terms.

In writing and signed

The agreement should be a written document signed by both parties before the marriage. Oral premarital agreements will not hold up in a Missouri court.

Entered freely, fairly, and knowingly

Under Ferry v. Ferry, both parties must sign without pressure and with a real understanding of what they are giving up. Courts look at each person's age, education, sophistication, and bargaining position.

Full financial disclosure

Each party must fully disclose their assets, debts, and income before signing. Because disclosure is baked into Missouri's core test, hiding or lowballing assets is the fastest way to lose the entire agreement.

Conscionable terms, with time and counsel

Missouri courts weigh whether each party had access to their own attorney and enough time to review the agreement. A grossly one-sided deal signed days before the wedding is exactly what gets thrown out.

What you can & can't include

You can include

  • Defining separate vs. marital property
  • How property and income acquired during marriage are treated
  • Responsibility for premarital and marital debt
  • Limiting or waiving spousal maintenance
  • Protecting a business, farm, inheritance, or professional practice
  • Estate and inheritance rights between spouses

You can't include

  • Child custody or parenting-time arrangements
  • Child support obligations
  • Unconscionable or grossly one-sided terms
  • Lifestyle clauses about personal behavior
  • Anything illegal or against public policy

Missouri prenup quick facts

Governing statuteCommon law — Ferry v. Ferry, 586 S.W.2d 782 (Mo. App. 1979) (no UPAA)
Property divisionEquitable distribution
NotarizationRequired — marriage contracts must be acknowledged or proved like conveyances of land (Mo. Rev. Stat. § 451.220); online notarization is included for Missouri couples
Waiting periodNone required — but sign well before the wedding
Spousal supportMaintenance can be limited or waived if the agreement is conscionable

See how Missouri's signing formalities compare in our prenup notarization requirements by state guide.

How Missouri courts evaluate enforcement

Missouri courts set prenups aside when the Ferry v. Ferry test fails — the agreement wasn't entered freely and knowingly, financial disclosure fell short, or the terms were unconscionable.

Because Missouri's standard is court-made, judges have real latitude to examine how the agreement came together: who had a lawyer, how much time each party had to review it, the parties' relative bargaining power, and whether every asset and debt was on the table. An agreement pushed on a fiancé shortly before the wedding, or one built on incomplete disclosure, is vulnerable. A fully disclosed, unrushed, two-sided agreement is what Missouri courts routinely enforce.

How to get a valid Missouri prenup for $599

Trusted Prenup creates a state-specific Missouri prenuptial agreement online — built to meet the requirements above and designed by James Sexton, Esq. A traditional attorney typically costs $2,500–$10,000; this is a flat $599.

1

Answer a few questions

A guided questionnaire captures your assets, debts, and wishes — most couples finish in under 90 minutes.

2

Generate your agreement

We assemble a complete prenup built to meet your state's exact legal requirements.

3

Review, sign & notarize

Review with your partner, then sign online with notarization handled for you.

Missouri note: Online notarization is included for Missouri couples. Sign well before the wedding so no one can claim last-minute pressure.
Start Your Missouri Prenup →

Missouri prenup FAQ

How much does a prenup cost in Missouri?

A Missouri attorney-drafted prenup commonly costs $2,000-$7,500 or more. Trusted Prenup creates a state-specific Missouri prenup online for a flat $599, with online notarization included and an optional attorney-review add-on.

Does a Missouri prenup need to be notarized?

Yes — Missouri marriage contracts must be acknowledged or proved in the manner required for conveyances of land (Mo. Rev. Stat. § 451.220). That is why online notarization is included, not optional, for every Missouri couple at checkout.

Can a prenup be challenged in Missouri?

Yes. Under Ferry v. Ferry, a Missouri prenup can be set aside if it wasn't entered freely, fairly, knowingly, and in good faith with full disclosure, or if its terms are unconscionable. Full disclosure and unhurried signing are the best protection.

Is Missouri a UPAA state?

No. Missouri never adopted the Uniform Premarital Agreement Act, so prenups are governed by common law — chiefly Ferry v. Ferry, 586 S.W.2d 782 (Mo. App. 1979) — rather than a statute.

Can spousal maintenance be waived in a Missouri prenup?

Yes, Missouri courts will enforce a maintenance waiver if the agreement satisfies the Ferry test and isn't unconscionable. A waiver that would leave one spouse destitute is at real risk of being set aside.

Do both people need a lawyer for a Missouri prenup?

It isn't legally required, but access to independent counsel is one of the factors Missouri judges weigh when deciding whether an agreement was fairly made. Trusted Prenup offers an optional attorney-review add-on to cover this.

Is an online prenup valid in Missouri?

Yes — Missouri enforces properly executed prenuptial agreements regardless of how they were drafted. What matters is execution: a written agreement, voluntary signatures, full financial disclosure, and Missouri's signing formalities. The full picture is in are online prenups legally binding.

More state prenup guides

Trusted Prenup is not a law firm and does not provide legal advice. This guide is general information about Missouri law and not a substitute for advice from a licensed attorney about your situation.