Prenuptial Agreements: What Can and Can’t Be Included in Your Contract?
Aug. 13, 2025
A prenuptial agreement, commonly referred to as a prenup, is a written contract between two people who plan to marry. It sets the financial terms of the relationship, defining each person's rights regarding property, debts, and support in the event of divorce or death.
While these contracts can be extremely useful, there are specific rules in Washington State about what can and can’t be included.
Prenups aren’t just for the wealthy or high-profile couples you read about in headlines. They’re valuable legal tools for anyone who wants to protect personal assets, define financial boundaries, or avoid future disputes. When approached early and thoughtfully, a prenup can actually strengthen the relationship.
As a family law attorney in Seattle, Washington, I guide each person through the process with clarity and care to help them create an agreement that meets Washington’s legal standards and reflects their unique situation. Learn more from me at Hallack Law, PLLC.
What Is a Prenuptial Agreement?
A prenuptial agreement is used to establish how a couple will divide assets and handle finances both during and after the marriage. It allows each party to define separate and community property, set expectations for financial responsibilities, and even address some aspects of spousal support.
Though often viewed as a tool for the wealthy, prenups are useful for many couples, especially when either person owns a business, carries debt, or has children from a previous relationship.
Having an agreement in place doesn’t mean the couple expects the marriage to fail. It simply offers protection and clarity. In a community property state like Washington, where nearly all assets gained during marriage are considered shared, a prenup allows couples to define terms that differ from the default rules.
Washington’s Approach to Prenups
Under Washington law, a prenuptial agreement is enforceable if it meets several legal requirements. Courts will generally uphold the contract as long as:
Both individuals signed voluntarily
The agreement wasn’t unconscionable at the time of signing
Each party had full and fair disclosure of the other's financial situation
Neither person was coerced nor unduly pressured
A well-drafted prenup not only meets these criteria but also avoids terms that conflict with public policy or state law. As a family law attorney, I always advise people to begin the process early—well in advance of the wedding date—and to have legal counsel on both sides.
What You Can Include in a Prenup
Here are some categories to add to a prenup:
Definition of Separate Property
One of the most important elements in any prenuptial agreement is the classification of separate and community property. This is especially critical for anyone entering marriage with real estate, a business, or other valuable assets. The agreement can specify that such assets—and their future appreciation—remain separate property.
Division of Debt
Prenups are equally useful when it comes to dividing financial obligations. If one party brings in significant debt, the agreement can state that those debts remain that person's sole responsibility. This protects the other spouse from financial exposure.
Spousal Support Terms
Spousal support, or alimony, may be addressed in a prenuptial agreement. The contract can waive support altogether or define limits in advance. However, Washington courts can modify or disregard these terms if enforcing them would be unjust, especially if one spouse would be left without the ability to meet basic needs.
Business Protections
Business owners often include clauses to keep their company from becoming marital property. A prenup can define how the business will be valued, how it should be treated during divorce, and whether income generated by the business remains separate.
Inheritance and Estate Planning
For those with children from previous relationships or specific estate goals, a prenup can clarify how inheritance will work. The agreement may outline what happens to separate property upon death and limit a spouse’s rights to inherit certain assets. Work with a family law attorney to better understand this process.
Retirement and Investment Accounts
Prenups can determine how retirement savings, pensions, and investment accounts will be classified. They can clarify which funds are subject to division and which aren’t, avoiding disputes down the road.
Household Expenses and Banking
Some couples choose to include terms about how they’ll handle daily finances during the marriage. While not all such terms are legally enforceable, they can serve as a structure for communication and agreement on budgeting and financial responsibilities.
What You Can’t Include in a Prenup
Child Custody and Child Support
Washington law prohibits prenups from determining child custody or child support in advance. Courts must base these decisions on the child’s best interests at the time of separation or divorce. Any attempt to pre-decide these issues in a contract will be disregarded.
Unfair or Unreasonable Terms
If a court finds that the agreement heavily favors one spouse or was signed without a full understanding of its terms, it may not be enforced. That’s why I always stress the importance of full disclosure and independent legal advice for both parties.
Personal or Lifestyle Clauses That Cross Legal Boundaries
While some couples include clauses about household rules or lifestyle preferences, provisions that attempt to control behavior (such as appearance, weight, or intimacy) won’t be enforced. Courts are unlikely to uphold anything that interferes with personal autonomy or contradicts public policy.
Incentives for Divorce
Agreements that provide rewards or benefits upon divorce may be considered contrary to public policy. Courts don’t support clauses that seem to encourage the end of the marriage.
Common Mistakes People Make With Prenups
Not Hiring Separate Legal Counsel
Each party should have its own family law attorney. This not only protects their interests but also adds credibility to the agreement. Courts are more likely to enforce a prenup when both parties have received independent legal advice.
Waiting Until the Last Minute
Signing a prenup a few days before the wedding can raise concerns about duress or coercion. I recommend starting the process several months in advance, allowing ample time for review and discussion.
Failing to Disclose Assets or Debts
Omitting financial information can make the agreement invalid. Both individuals must provide a clear and honest overview of their financial circumstances at the time of signing.
Using DIY Templates or Generic Contracts
Online forms might seem convenient, but they rarely comply with state laws or address personal situations. A cookie-cutter document won’t stand up in court if it’s missing required disclosures or improperly worded.
Who Should Consider a Prenup?
Prenuptial agreements are useful for more than just high-net-worth individuals. I often recommend considering a prenup if:
One or both parties have significant assets
There’s a family business involved
Either person has children from a prior relationship
One party earns significantly more than the other
There are existing debts
The couple wants to maintain financial independence
Even when a prenup is never needed, having one in place can offer peace of mind. It creates a transparent conversation about expectations, which often strengthens the relationship.
Reach Out to a Family Law Attorney Today
If you're getting married in Seattle and want to explore your options, I’d be happy to help. Serving Seattle, Washington, and throughout King County, Washington, including Bellevue, Renton, Kent, Auburn, Enumclaw, Issaquah, Snoqualmie, North Bend, Kirkland, Redmond, Woodinville, and Skykomish, I’m here to help.
As a family law attorney, I offer the support and legal clarity you need. Contact Hallack Law, PLLC today to schedule a consultation and begin the process with confidence.