Can a Prenup Be Thrown Out in Oregon? 2026 Enforceability Guide

A prenup can be thrown out in Oregon under Or. Rev. Stat. § 108.725 if the challenging spouse proves the agreement was signed involuntarily, or that it was unconscionable when executed AND there was no fair financial disclosure. Oregon courts decide unconscionability as a matter of law, and unconscionability alone is never enough to void an agreement.

Oregon adopted the Uniform Premarital Agreement Act (UPAA) in 1987, codified at Or. Rev. Stat. § 108.700 to 108.740. This framework makes prenups generally enforceable while giving challengers two narrow paths to invalidation. Understanding exactly when a prenup can be thrown out in Oregon requires knowing the precise statutory standard, the burden of proof, and the key court decisions interpreting them. This guide explains every ground for challenging a prenup, the 2026 procedures, costs, and what Oregon courts actually require.

Key Facts: Prenups and Divorce in Oregon (2026)

What Does It Mean to Throw Out a Prenup in Oregon?

To throw out a prenup in Oregon means a court declares the agreement unenforceable under Or. Rev. Stat. § 108.725, so the divorce proceeds as if no agreement existed. When this happens, property is divided under equitable distribution per ORS § 107.105 and spousal support is set by statute. The challenging spouse carries the entire burden of proof.

Oregon law presumes a properly executed premarital agreement is valid and enforceable. The statute lists specific circumstances that make an agreement unenforceable, and case law confirms that, impliedly, a premarital agreement is enforceable absent those circumstances. This means the spouse who wants to escape the prenup must affirmatively prove one of the statutory grounds — the spouse seeking enforcement does not have to prove the agreement is fair. A premarital agreement under ORS § 108.705 must be in writing and signed by both parties, and it is enforceable without consideration, so the formal bar to entry is low while the bar to invalidation is high.

What Are the Legal Grounds to Throw Out a Prenup in Oregon?

Oregon recognizes exactly two grounds to throw out a prenup under Or. Rev. Stat. § 108.725: involuntary execution, or unconscionability combined with a failure of fair financial disclosure. The challenging spouse must prove one of these by the applicable evidentiary standard. Roughly half of successful challenges nationally turn on voluntariness rather than financial disclosure.

Under ORS § 108.725(1), a premarital agreement is not enforceable if the party against whom enforcement is sought proves that: (a) that party did not execute the agreement voluntarily; or (b) the agreement was unconscionable when it was executed and, before execution, that party was not provided fair and reasonable disclosure of the other party's property or financial obligations, did not voluntarily and expressly waive that disclosure in writing, and did not have (and reasonably could not have had) adequate knowledge of the other party's property or financial obligations. The statutory structure is critical: the two grounds are independent, but the second ground requires proving every element of a three-part disclosure test in addition to unconscionability. This makes an invalid prenup harder to establish in Oregon than in states that allow unconscionability alone.

Can a Prenup Be Thrown Out for Lack of Voluntariness in Oregon?

Yes. A prenup can be thrown out in Oregon if the challenging spouse proves it was not signed voluntarily under Or. Rev. Stat. § 108.725(1)(a). Oregon courts define voluntariness as requiring knowledge of the agreement's terms and the property affected, plus a lack of coercion, intimidation, or undue pressure. This is the single most common basis for challenging prenup enforceability in Oregon.

The leading case is Rudder and Rudder, 230 Or App 437, 217 P3d 183 (2009), where the Oregon Court of Appeals upheld a trial court ruling that a premarital agreement was unenforceable because the wife proved she did not enter it voluntarily. The court defined the standard precisely: voluntariness implies knowledge of the terms of the agreement and the property affected by those terms, and the absence of coercion, intimidation, or undue pressure. Factors Oregon courts examine include how many days before the wedding the agreement was presented, whether the challenging spouse had time to read and understand it, whether independent legal counsel was available, and the relative bargaining power of the parties. The presence or absence of independent counsel does not, by itself, void an agreement, but courts have noted it can be important in determining whether there has been foul play in the negotiation process.

When Is a Prenup Unconscionable in Oregon?

A prenup is unconscionable in Oregon when its terms are so one-sided or oppressive that enforcement would shock the conscience, and the court decides this question as a matter of law under Or. Rev. Stat. § 108.725. Critically, unconscionability alone is insufficient to invalidate an agreement — the challenging spouse must also prove the three-part disclosure failure.

The legislative history is explicit on this point. Lawrence Young, former chair of the Oregon Uniform State Laws Committee, explained that under the provision codified as ORS § 108.725(1)(b), unconscionability alone is insufficient to render an agreement unenforceable. An agreement that is merely unconscionable — meaning unconscionable, but where the disclosure elements have not been proved — will not be invalidated. This is a key distinction from many other states. Because Oregon law assigns the unconscionability determination to the judge as a matter of law rather than the jury, the timing reference matters: the agreement is judged for unconscionability as of when it was executed, not as of the divorce. A prenup that became lopsided years later because one spouse's wealth grew dramatically is not unconscionable under Oregon's standard, since the measurement date is fixed at signing.

How Does Financial Disclosure Affect Prenup Enforceability in Oregon?

Financial disclosure is decisive for the second invalidation ground in Oregon. To throw out a prenup as unconscionable under Or. Rev. Stat. § 108.725(1)(b), the challenger must prove all three disclosure failures: no fair and reasonable disclosure, no written express waiver of disclosure, and no adequate independent knowledge of the other party's finances. Failing to prove any one element defeats this ground.

Legal commentary on Oregon's UPAA confirms that a valid prenuptial agreement should be in writing, signed by both parties, and supported by full financial disclosure to be reliably enforceable. The three-part test creates a practical safe harbor for the drafting spouse: even if disclosure was incomplete, the agreement survives if the challenging spouse either signed a written waiver of disclosure or reasonably could have known the other party's financial situation. This is why well-drafted Oregon prenups attach detailed asset and debt schedules and include an express written waiver clause. The statute's tolling rule under ORS § 108.735 provides that any statute of limitations on a claim under a premarital agreement is tolled during the marriage, though equitable defenses such as laches and estoppel remain available to either party. This means a spouse generally cannot lose the right to challenge a prenup simply because years passed during the marriage.

Can a Prenup Waiving Spousal Support Be Thrown Out in Oregon?

Yes, a prenup waiving spousal support can be partially thrown out in Oregon if enforcement would leave a spouse unable to obtain necessary support elsewhere. Under Or. Rev. Stat. § 108.725, if a support waiver causes one party undue hardship in light of circumstances not reasonably foreseeable at signing, the court may order support despite the waiver.

The governing case is Bridge and Bridge, 166 Or App 458, 998 P2d 780 (2000), which held that a prenuptial agreement waiving spousal support is enforceable unless enforcement deprives a spouse of necessary support that cannot be obtained elsewhere. This is a hardship safety valve rather than a general fairness review. A spouse who waived support but can still meet basic needs through employment, separate property, or public benefits will typically have the waiver enforced. By contrast, a spouse who would be left destitute and unable to obtain support from any other source may receive court-ordered support to the extent necessary to avoid that hardship. Oregon courts treat property division provisions and spousal support provisions differently — a support waiver gets this extra hardship review, while property terms are tested only against the involuntariness and unconscionability-plus-disclosure standards.

What Subjects Can and Cannot Be Included in an Oregon Prenup?

Oregon prenups may govern property rights, asset disposition on divorce or death, and spousal support, but they cannot adversely affect child support under Or. Rev. Stat. § 108.710. Any clause attempting to waive or reduce a child's right to support is unenforceable and will be struck regardless of how the rest of the agreement holds up.

Under ORS § 108.710, parties may contract with respect to the rights and obligations of each in property, the right to manage and control property, the disposition of property on separation or dissolution, the modification or elimination of spousal support, and the making of a will or trust. The single firm limit is that the right of a child to support may not be adversely affected by a premarital agreement. This reflects Oregon's policy that child support belongs to the child, not the parents, so spouses cannot bargain it away in advance. A second limit appears in ORS § 108.730: if a marriage is determined to be void, an agreement that would otherwise have been a premarital agreement is enforceable only to the extent necessary to avoid an inequitable result. Modifications after marriage require a new written agreement signed by both parties under ORS § 108.720, and like the original, it is enforceable without consideration.

How Much Does It Cost to Challenge a Prenup in Oregon?

Challenging a prenup in Oregon adds litigation cost to the base divorce filing fee of $301 (as of February 2026; verify with your local clerk). A contested prenup challenge typically requires depositions, financial experts, and trial preparation, pushing total attorney fees into the range of $15,000 to $50,000 or more depending on asset complexity and how vigorously enforcement is contested.

The dissolution filing fee in Oregon is $301 statewide across all 36 circuit courts as of February 2026, with slight county variation reported between approximately $273 and $301. That fee does not include the cost of litigating prenup enforceability. Because ORS § 108.725 requires the challenger to prove either involuntariness or unconscionability-plus-disclosure-failure, a serious challenge usually involves discovery into the circumstances of signing, financial records from the time of execution, and sometimes expert testimony on asset values. Low-income filers may qualify for a fee waiver or deferral of the $301 filing fee — eligibility generally requires household income below 200% of the federal poverty level or receipt of benefits such as SNAP or TANF. Note that the filing-fee waiver covers court costs, not attorney fees. Oregon courts can, in some dissolution cases, order one spouse to contribute to the other's attorney fees, which can offset the cost of a meritorious prenup challenge.