What Is a Sunset Clause in a Prenup?

A sunset clause is a term in a prenuptial agreement that makes the whole agreement, or certain parts of it, stop applying after a set period of marriage (for example, 10 years) or when a specified event happens, such as the birth of a child. Prenups don't expire on their own; they last until the spouses revoke or amend them in a signed writing. A sunset clause is how couples build an end date in from the start. State premarital-agreement statutes generally let couples set terms that depend on "the occurrence or nonoccurrence of any other event," so a clearly written sunset clause is usually treated like any other term. It still has to pass the state's enforceability tests, and it can't touch child support.

At a glance

How a sunset clause works

A prenup usually sets out what stays separate property, how marital property is divided, and whether either spouse waives or limits spousal support or inheritance rights. A sunset clause adds a condition: those terms apply only until a stated date or event. Common triggers include:

• A marriage anniversary, such as the 5th, 10th or 15th.
• The birth or adoption of a child.
• Another defined event the couple chooses, for example a business sale or a move to another state.

The clause can be full (the entire agreement ends) or partial (only some terms end, such as a spousal-support waiver, while separate-property terms stay). Some couples choose a step-up instead of a cliff: terms that change in stages, such as support rights that increase with each year of marriage. Whatever the structure, the agreement itself is the only source of the rule, so the wording matters.

Is a sunset clause enforceable?

There is no special statute for sunset clauses. Courts treat them as part of the premarital agreement, so the question is whether the agreement as a whole is enforceable, and then what the clause means.

What the statutes allow. States that adopted the Uniform Premarital Agreement Act (UPAA) let couples contract about the disposition of property "upon separation, marital dissolution, death, or the occurrence or nonoccurrence of any other event," and about "any other matter" that doesn't violate public policy or a criminal statute (N.C. §52B-4(a); Fla. §61.079(4)(a)). Connecticut's own act uses the same event language (§46b-36d(a)(3)) and adds that an agreement takes effect on marriage "unless otherwise provided in the agreement" (§46b-36e). North Dakota's version of the newer Uniform Premarital and Marital Agreements Act (UPMAA) defines a premarital agreement to include rights that arise on the "occurrence or nonoccurrence of any other event" (N.D. Cent. Code §14-03.2-01).

What can still sink the agreement. A sunset clause doesn't save an agreement that fails the state's test, and a valid sunset clause doesn't make an invalid agreement valid. Examples:

• UPAA states (e.g., North Carolina, Texas): the agreement isn't enforced if the challenging spouse proves they didn't sign voluntarily, or that it was unconscionable when signed and, before signing, they didn't get fair and reasonable financial disclosure, didn't waive it in writing, and didn't otherwise know the other's finances (N.C. §52B-7; Tex. Fam. Code §4.006).
• Florida adds agreements that were "the product of fraud, duress, coercion, or overreaching" (§61.079(7)(a)).
• Connecticut refuses enforcement if the agreement was unconscionable "when it was executed or when enforcement is sought," if disclosure wasn't fair and reasonable, or if a spouse wasn't given a reasonable opportunity to consult independent counsel (§46b-36g).
• California requires independent counsel or a written waiver, and for agreements signed on or after Jan. 1, 2020, at least seven calendar days between first being presented with the final agreement and signing it (Fam. Code §1615(c)). Spousal-support terms are unenforceable without independent counsel for the party giving up support, or if they're unconscionable at the time of enforcement (§1612(c)).
• North Dakota (UPMAA) looks at access to independent legal representation, a plain-language explanation of rights being waived (unless represented), and adequate financial disclosure. A court may also refuse a term whose enforcement "would result in substantial hardship for a party because of a material change in circumstances arising after the agreement was signed" (§14-03.2-08).

What no clause can do. Under every statute above, a premarital agreement can't adversely affect a child's right to support. If a support waiver would leave a spouse eligible for public assistance at divorce, UPAA-style statutes let the court order support to the extent needed to avoid that (N.C. §52B-7(b); Fla. §61.079(7)(b); Conn. §46b-36g(b)). North Dakota's UPMAA also bars terms that limit domestic-violence remedies or penalize a spouse for filing for divorce (§14-03.2-09).

Why couples use one, and why some don't

Reasons to add a sunset clause:

• A spouse who signs from a weaker financial position gets a defined point after which the agreement stops limiting their rights.
• It reflects the idea that a long marriage is a different bargain from a short one.
• Negotiations can be easier when one side worries mainly about an early divorce.

Reasons to leave it out:

• Protection for family businesses, inherited wealth or pre-marriage assets can vanish on a fixed date. That date usually arrives before the larger assets do.
• A cliff date can create pressure around an anniversary, and a dispute over whether a divorce filed near the date counts.
• Some of the fairness goals can be met in other ways: step-ups, updating the agreement by postnup, or (in states such as Connecticut, California and North Dakota) the court's own look at fairness at the time of divorce.

What happens when the sunset date passes

For any terms that sunset, the agreement no longer controls, and the state's default rules apply as if the couple had never agreed on those terms. That generally means the state's property-division rules (community property or equitable distribution), its spousal-support law and its inheritance rights for a surviving spouse. Terms that don't sunset keep working. Check whether a full sunset also ends waivers that apply at death, not just divorce. Estate plans built around the prenup may need updating at the same time.

Drafting points to settle up front

• What date counts. Measure the time to the wedding date and then to what: the filing of a divorce petition, a separation, or the final decree? Say so.
• Filed-then-dismissed cases. What happens if one spouse files before the sunset and the case is later dismissed or reconciled?
• Partial vs. full. List exactly which sections end and which survive, including death-related waivers.
• Records. Keep separate-property records even if the separate-property terms may sunset. They may still matter under state default law.
• Copies. In an unpublished 2016 Kansas Court of Appeals case, a wife argued that the signed agreement had included a sunset page, since missing, voiding it after 10 years of marriage or the birth of a first child. The trial court found she hadn't proved it and enforced the agreement (In re Marriage of Irons, No. 114,055). Keep complete, signed, initialed copies of every page with both spouses and both lawyers.
• Choice of law. If the couple may move, state which state's law governs. UPAA statutes allow a choice-of-law term (e.g., N.C. §52B-4(a)(7); Fla. §61.079(4)(a)7.).

Changing course: amend instead of sunset

Couples who didn't include a sunset clause, or want to change one, can amend or revoke the prenup after marriage, but only by a written agreement signed by both spouses (N.C. §52B-6; Tex. Fam. Code §4.005; Conn. §46b-36f). Florida's statute also says an agreement can be "abandoned" only by a signed writing (§61.079(6)). States that use the UPMAA, such as North Dakota, apply the same signing, disclosure and counsel safeguards to agreements made during marriage (§14-03.2-05, -08). See What Is a Postnuptial Agreement?.

Find a family law attorney

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Featured: Haute Lawyer members who handle prenuptial agreements include Amber Kornreich (Florida Bar Board Certified Marital and Family Law attorney and partner at Kornreich & Associates in Miami, whose practice includes sophisticated prenuptial and postnuptial agreements) and Frederic J. Siegel (founder and managing partner of Siegel, Colin & Kaufman, P.C. in Stamford, Connecticut, who handles prenuptial and postnuptial agreements alongside divorce and custody matters).

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Related pages

• What Is a Prenup — and Who Actually Needs One?
• Can a Prenuptial Agreement Be Challenged?
• What Is a Postnuptial Agreement?
• How Do Prenups Work for High-Net-Worth Couples?
• How to Find a Good Prenup Attorney

This page is general information, not legal advice. Premarital-agreement law varies by state and changes over time; talk with a family law attorney licensed in your state before signing or relying on a prenup.