Prenuptial Agreement Requirements in Wyoming

At a glance

Requirements one by one

Wyoming uses a Statute of Frauds plus case law

Wyoming has not enacted a comprehensive Uniform Premarital Agreement Act. Wyo. Stat. § 1-23-105(a) supplies the writing rule, while Laird v. Laird, Lund v. Lund, and Jones v. Young supply the contract, disclosure, and unconscionability framework.

The default divorce backdrop remains Wyo. Stat. § 20-2-114(a), which directs a just and equitable property disposition and authorizes reasonable alimony. Lund nevertheless requires the court to honor a valid antenuptial agreement unless it records a cogent reason for refusing enforcement.

The charged party must subscribe a writing

Section 1-23-105(a) makes a marriage-consideration agreement void unless the agreement, or a note or memorandum of it, is written and subscribed by the party charged. A mutually enforceable prenup therefore ordinarily carries both prospective spouses' signatures, even though the statute states the rule from the perspective of the person against whom enforcement is sought.

Under Lund, the contemplated marriage is the consideration that binds both parties. A separate payment is not required for the premarital bargain.

Wyoming adds no universal notary or witness step

The Statute of Frauds calls for writing and subscription. It does not add a prenup-specific notary, acknowledgment, witness, attestation, oath, or recording requirement for enforcement between the spouses.

A deed, estate instrument, or other document used to carry out a particular term can have its own execution or recording rules. Those rules do not become universal prenup formalities.

Detailed net-worth schedules are not always indispensable

Laird rejected a rule requiring a financial statement of net worth and income in every case. The signer there knew the other prospective spouse was a person of substantial wealth, had observed extensive holdings and income, and agreed to renounce any interest without evidence of deliberate concealment or overreaching.

That holding is fact-specific. Fraud, deceit, overreaching, lack of understanding, or material concealment can still defeat enforcement. Wyoming has no UPAA-style statute prescribing a separate written waiver of further disclosure.

Counsel and wedding timing are part of meaningful choice

Wyoming fixes no number of review days before the wedding and does not make actual separate counsel a universal statutory condition. The process still matters. Jones identifies compulsion, opportunity for meaningful negotiation, gross bargaining inequality, the challenger's education and vulnerability, and surprise from fine print or concealed terms as procedural factors.

Laird likewise emphasized the absence of pressure, rushing, influence, or a denied opportunity to read. A signature alone does not erase proven fraud or overreaching, but a capable signer normally cannot avoid clear terms merely by choosing not to read them.

Fairness is measured when the bargain is made

The fairness source is case law. Laird reviews a prenup as a contract and asks whether it was understandingly made and freely executed, without fraud, deceit, or overreaching. Jones supplies Wyoming's current unconscionability framework: the court balances substantively one-sided terms against the lack of a meaningful procedural choice, and both must be present.

The unconscionability inquiry is measured when the contract was made, not with hindsight. That formation-time rule does not create a general divorce-time power to revise a bargain merely because the spouses' circumstances later diverge.

A support waiver can be enforced

Seherr-Thoss enforced a premarital agreement that expressly waived spousal support and substituted scheduled annual payments plus a length-of-marriage lump sum as the full settlement of property and alimony issues. The trial court found the agreement fair and equitable, knowingly and willingly made, and free of fraud or duress; the Supreme Court applied ordinary contract rules.

Wyoming's prenup authorities do not create the generic public-assistance or enforcement-time unconscionability safety valve found in some uniform-act states. Formation validity and the agreement's actual terms therefore remain central.

Child support and custody remain with the court

Wyo. Stat. § 20-2-201(a) directs the court to make a child disposition that is most expedient and in the child's best interests. In Combs, the Supreme Court held that parents cannot contract away a child's right to adequate support and that a custody term contrary to the court's statutory authority is void as against public policy.

A prenup may record the parents' expectations, but it cannot conclusively cap support or dictate custody without judicial review.

A later change becomes a postnuptial contract

Lund recognizes that spouses may modify a prenup after marriage through a further agreement, subject to the applicable formal requirements and the original agreement's terms. The postmarriage agreement enters a distinct contract lane.

Under Combs and Jones, the existing marriage is not fresh consideration for that later contract. The spouses need other identifiable consideration, such as exchanged promises, forbearance, or another alteration of legal rights.

What trips people up

• A wealth estimate can be enough in the right facts. Laird did not make detailed schedules irrelevant; it held that their absence alone did not invalidate an agreement where the signer already knew substantial wealth existed and no concealment or overreaching was shown.
• Formation-time unconscionability is not a later fairness reset. Jones measures the issue when the contract was made and requires both substantive and procedural unconscionability.
• A postmarriage amendment needs new consideration. The marriage supports the original prenup, but the already-existing marriage cannot support a later amendment by itself.

Common questions

Does a Wyoming prenup need notarization?

The governing Statute of Frauds requires a writing subscribed by the party charged. It does not impose a prenup-specific notary or witness requirement.

Must each prospective spouse have a lawyer?

No statute or controlling case makes actual separate counsel universally mandatory. Lack of advice can still matter to whether the signer had a meaningful choice, understood the agreement, and was subjected to overreaching.

Can a prenup set child support at a fixed amount?

It cannot bind the court. Combs holds that parents may not contract away the child's right to adequate support, and Wyoming law leaves custody and support decisions under judicial control.

Statutes and sources

• Wyo. Stat. § 1-23-105(a) — writing and subscription by the party charged for an agreement made upon consideration of marriage. Wyoming Legislature Title 1 (accessed 2026-07-28).
• Wyo. Stat. §§ 20-2-114(a) and 20-2-201(a) — default property, alimony, and best-interest authority. Wyoming Legislature Title 20 (accessed 2026-07-28).
• Laird v. Laird, 597 P.2d 463 (Wyo. 1979), and Lund v. Lund, 849 P.2d 731 (Wyo. 1993) — ordinary contract treatment, disclosure, understanding, free execution, marriage as consideration, and later modification. Laird and Lund (accessed 2026-07-28).
• Jones v. Young, 2025 WY 130 — formation-time substantive and procedural unconscionability. Opinion (accessed 2026-07-28).
• Seherr-Thoss v. Seherr-Thoss, 2006 WY 111 — enforcement of a prenup with an express support waiver and lump-sum settlement. Opinion (accessed 2026-07-28).
• Combs v. Sherry-Combs, 865 P.2d 50 (Wyo. 1993) — child-support and custody public-policy limits and new consideration for a postnuptial agreement. Opinion (accessed 2026-07-28).