Everything engaged couples need to know about making a prenuptial agreement valid and enforceable in Washington — in plain English, reviewed by attorney James Sexton, Esq.
Yes — prenuptial agreements are legal and enforceable in Washington, governed by the two-prong fairness test from In re Marriage of Matson rather than a statute.
Washington is a community property state (RCW 26.16.030) that never adopted the Uniform Premarital Agreement Act, so prenups are governed by Washington Supreme Court case law. The controlling standard is the two-prong test from In re Marriage of Matson, 107 Wn.2d 479 (1986), reaffirmed in In re Marriage of Bernard, 165 Wn.2d 895 (2009). A court first asks whether the agreement is substantively fair — whether it makes reasonable provision for the spouse not seeking enforcement. If it does, the inquiry ends and the prenup is enforced. If the agreement is one-sided, it can still survive, but only by passing the procedural-fairness prong: full disclosure of all assets and a meaningful, unpressured opportunity for each party to consult independent counsel.
A Washington prenup is enforceable if it is substantively fair to both spouses, or — where it heavily favors one spouse — if it was signed with full disclosure, independent-counsel opportunity, and no time pressure.
The agreement should be a written document signed by both parties. Washington courts analyze it as a contract layered with the Matson fairness test.
If the agreement makes fair and reasonable provision for the non-enforcing spouse, the analysis stops there and the prenup is valid. Balanced terms are the cheapest insurance a Washington couple can buy.
A one-sided agreement survives only if both parties fully disclosed their assets and each had a real opportunity for independent legal advice, with enough time to use it. Bernard invalidated terms signed days before the wedding.
Each party must lay out all assets, debts, and income. Hidden or vaguely described property is a classic reason Washington prenups fail the procedural prong.
| Governing statute | No statute — Washington case law (In re Marriage of Matson, 107 Wn.2d 479 (1986); In re Marriage of Bernard, 165 Wn.2d 895 (2009)) |
|---|---|
| Property division | Community property |
| Notarization | Recommended (not required by statute) |
| Waiting period | None required — but sign well before the wedding |
| Spousal support | Maintenance can be limited or waived, subject to the Matson fairness test |
See how Washington's signing formalities compare in our prenup notarization requirements by state guide. Washington is also one of the nine community-property states — community property vs. equitable distribution explains what that default means for your agreement.
Washington courts strike down prenups that are one-sided and were signed without full disclosure, independent-counsel opportunity, or adequate time — the combination Matson and Bernard call procedurally unfair.
The pattern in the case law is consistent: a balanced agreement is enforced without much scrutiny, while a lopsided one gets its signing circumstances put under a microscope. In Bernard, the Washington Supreme Court refused to enforce amendments signed days before the wedding, when the disadvantaged spouse had no realistic chance to get independent advice. For Washington couples the playbook is simple — disclose everything, give each other time and access to separate lawyers, and keep the terms fair enough that a judge never reaches prong two.
Trusted Prenup creates a state-specific Washington 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.
A guided questionnaire captures your assets, debts, and wishes — most couples finish in under 90 minutes.
We assemble a complete prenup built to meet your state's exact legal requirements.
Review with your partner, then sign online with notarization handled for you.
A Washington attorney-drafted prenup typically costs $2,500–$10,000+, and more in Seattle. Trusted Prenup creates a state-specific Washington prenup online for a flat $599, with optional notarization and attorney-review add-ons.
No — Washington has no statute requiring notarization of a premarital agreement. It is still recommended, because notarized signatures are far harder to contest under the procedural-fairness prong.
Yes — under the Matson two-prong test. A challenger wins by showing the agreement is substantively unfair and was also procedurally unfair: incomplete disclosure, no real chance for independent counsel, or last-minute signing pressure.
From In re Marriage of Matson (1986): a court first asks whether the prenup makes fair and reasonable provision for the non-enforcing spouse. If yes, it's enforced. If not, it survives only if signing was procedurally fair — full disclosure plus independent-counsel opportunity for both parties.
Yes. Under RCW 26.16.030, property acquired during marriage is presumed community property owned equally by both spouses. A prenup is the main tool Washington couples use to opt out of those defaults.
There's no statutory deadline, but In re Marriage of Bernard invalidated terms signed days before the wedding. Aim to finalize and sign at least 30 days out, with time for each of you to consult independent counsel.
Yes — Washington enforces properly executed prenuptial agreements regardless of how they were drafted. What matters is execution: a written agreement, voluntary signatures, full financial disclosure, and Washington's signing formalities. The full picture is in are online prenups legally binding.
Trusted Prenup is not a law firm and does not provide legal advice. This guide is general information about Washington law and not a substitute for advice from a licensed attorney about your situation.