How Do I Invalidate a Prenuptial Agreement?

If you signed a prenuptial agreement and now believe it was unfair or that you never truly understood it, you may be able to challenge it. Washington courts will refuse to enforce a prenup that does not meet the standards our case law requires.

There Is No Statute, So the Cases Control

Washington has no statute that sets out when a prenuptial agreement is valid or invalid. Instead, the rules come from decisions of the Washington Supreme Court. The two leading cases are In re Marriage of Matson, 107 Wn.2d 479 (1986), which established the framework, and In re Marriage of Bernard, 165 Wn.2d 895 (2009), which applied that framework and reaffirmed how demanding it can be. Together these cases tell you what a challenger must show and what a court will look for.

Matson set out a two-part analysis. The court first asks whether the agreement made a fair and reasonable provision for the spouse who is not seeking to enforce it. This is the substantive fairness question. If the agreement was substantively fair, it can be upheld on that basis, and the inquiry may end there. But if the agreement was not substantively fair, the court moves to the second part and examines the fairness of the process that produced it. This is where most successful challenges live.

Substantive Unfairness Without a Fair Process

The core of a challenge is showing that the agreement is substantively unfair and that the process behind it was not fair enough to save it. Substantive unfairness looks at the deal itself: does the agreement leave one spouse with little or nothing while the other keeps everything, in a way that no reasonable person in that position would have accepted with full information? A lopsided agreement is not automatically void, but it opens the door to the second inquiry, where the burden effectively shifts to the party defending the agreement to show the process was fair.

Procedural fairness turns on the circumstances surrounding the signing. Courts weigh the relative bargaining positions of the parties, how sophisticated each spouse was, whether independent legal advice was present, whether each spouse understood the legal consequences and the rights they were surrendering, and the timing of the agreement relative to the wedding date. To uphold a prenup, Washington law generally requires full disclosure by both parties of all aspects of their assets, with the agreement entered into fully and voluntarily, on independent advice, and with each spouse's full knowledge of their individual rights. Fall short on those elements, and the agreement is vulnerable.

The Grounds That Actually Win

Several specific problems come up again and again in successful challenges. The first is a lack of full financial disclosure. If your spouse hid or understated assets so that you could not know what you were giving up, that undermines the agreement. Bernard makes the point sharply: a failure to provide full asset disclosure can void a prenup even where the challenging spouse had independent counsel. Disclosure is not a formality that other protections can excuse.

The second common ground is the absence of independent counsel. If you had no lawyer of your own, or shared your spouse's lawyer, or were steered away from getting advice, a court is far more skeptical that you understood what you signed. The third is coercion or a last-minute signing. An agreement presented for the first time days before the wedding, when the invitations are out and the guests are arriving, carries obvious pressure to sign. Bernard involved facts like these: the husband and his attorney had worked on the agreement for months, but the wife did not see a first draft until roughly eighteen days before the wedding, and then received a substantially different draft just three days before it. The court held the agreement unenforceable as both substantively and procedurally unfair. Timing that leaves one spouse no real chance to review, negotiate, or walk away is powerful evidence of an unfair process.

A fourth ground is the closely related problem of a spouse who did not sign knowingly and voluntarily. In Matson itself, the court found that the wife did not intelligently and voluntarily sign the agreement, and it was voided on that basis. Confusion about the terms, a language barrier, being rushed, or being misled about what the document meant can all support this kind of challenge.

How a Challenge Actually Proceeds

You raise a challenge to a prenup in the divorce case itself. When one spouse asks the court to enforce the agreement, the other can contest its validity, and the court decides the issue as part of dividing the estate and setting any maintenance. Practically, that means gathering evidence about how the agreement came together: what was disclosed, what was not, who had a lawyer, how much time passed between the first draft and the wedding, and what each party understood. Emails, drafts, financial records, and testimony about the days before the wedding all matter. Because the analysis is fact-intensive, the outcome often turns on details that only careful preparation will surface.

It is worth being realistic. A prenup that was fairly negotiated, fully disclosed, independently reviewed, and signed with time to spare is difficult to unwind, and courts do enforce those agreements. The agreements that fall are the ones where the process failed the people it was supposed to protect.

If you are in Snohomish County and facing a divorce where a prenuptial agreement stands between you and a fair result, it is worth having someone examine how that agreement was made. The Law Office of Chad Foster can review your circumstances, assess whether the agreement meets Washington's standards, and help you decide whether to challenge it. Reach out to talk through where you stand.