- Washington is an community property state — marital assets are split 50/50 by default.
- Notarization is recommended but not required for prenups in Washington.
- Witnesses are recommended but not legally required.
- Full financial disclosure by both parties is required by law.
- Washington has no mandatory waiting period, but signing at least 30 days before the wedding is recommended.
How Washington classifies marital property
Washington is a community property state. All assets and debts acquired during marriage are owned equally by both spouses, and this rule applies equally to registered domestic partnerships. One important caveat: if separate property is commingled with community funds — even inadvertently — it can lose its separate character. A prenup documents your pre-marital assets and establishes clear rules to prevent commingling from erasing separate property protections.
Understanding Washington's community property system is critical because a prenup is essentially your opportunity to override these default rules. Without one, everything earned during the marriage is split equally — regardless of who earned it.
The legal framework: RCW § 26.16; case law
Prenuptial agreements in Washington are governed by RCW § 26.16; case law. While Washington has not adopted the Uniform Premarital Agreement Act (UPAA), the state's statutes provide clear requirements for valid prenuptial agreements.
Signing requirements in Washington
Washington has specific requirements that must be met for a prenuptial agreement to be valid. Missing any of these can give a court grounds to throw out the entire agreement.
- **Written agreement** — Must be in writing — verbal prenups are not valid
- **Signed by both parties** — Both parties must sign voluntarily before the wedding
- **Notarization recommended** — Not legally required but strongly advised for court enforceability
- **Independent legal counsel recommended** — Each party should have their own attorney review the agreement
- **Full financial disclosure** — Both parties must disclose all assets, debts, and income — incomplete disclosure is the #1 reason prenups are invalidated
- **State-specific requirement** — Applies to registered domestic partnerships
- **State-specific requirement** — Separate property can lose status if commingled with community funds
Spousal support in a Washington prenup
Spousal support waivers are generally enforceable in Washington prenups, provided the agreement meets all other legal requirements — voluntary execution, full financial disclosure, and terms that are not unconscionable.
Sunset clauses and special provisions
Washington courts will enforce sunset clauses — provisions that cause the prenup to expire after a set number of years. If you want the agreement to remain in effect indefinitely, make sure to exclude a sunset clause or explicitly state that the agreement has no expiration.
Build your Washington prenup on Clause
Clause generates a legally valid, Washington-specific prenuptial agreement starting at $549 — a fraction of the $5,000–$20,000 that traditional attorney-drafted prenups cost in Washington. The Agreement Builder automatically handles Washington's signing requirements, and financial disclosure obligations. Attorney review and online notarization are available as add-ons.
Clause is not a law firm and this article is not legal advice. For guidance specific to your situation, consult a licensed family law attorney in Washington.