You thought you did everything right: before the wedding, you and your partner sat down with lawyers, hammered out a prenuptial agreement, signed on the dotted line, and filed it away. Everything’s copacetic, right? Well… it depends.
Prenups in California are often enforceable, but they’re not invincible. California law builds in several safety valves that can render even a signed, notarized premarital agreement unenforceable when things go sideways, and although this is California, we don’t mean drinking Pinot Noir from a Styrofoam cup Sideways. We mean, tossing the agreement out the window sideways.
The Two Big Dealbreakers: Voluntariness and Unconscionability
California Family Code gives courts two main grounds to invalidate a prenup:
- the agreement wasn’t signed voluntarily, or
- it was unconscionable at the time of signing, and one party didn’t have adequate financial disclosure.
Voluntariness is exactly what it sounds like: did you sign freely? Or were you coerced, rushed, or blindsided? Maybe your in laws sat you down days before the wedding and intimated the whole thing might be called off if you didn’t sign. Under those circumstances, even though your hand may have “voluntarily” traveled over the paper, that’s called coercion. California courts consider:
- Was the agreement sprung on you days before the wedding when the invitations were already mailed?
- Did you have your own lawyer, or at least a real chance to consult one?
- Did you understand what rights you were giving up?
Since 2002, California law presumes a prenup wasn’t voluntary unless certain safeguards were in place. If you weren’t represented by independent counsel when you signed, you needed at least seven calendar days between when you first saw the final agreement and when you signed it, and that seven-day clock doesn’t start until you were advised to get a lawyer. Since 2020, that seven-day clock is required even if you have counsel. Courts have invalidated agreements where the timeline was too tight or the party didn’t have meaningful opportunity to seek advice.
Unconscionability is the second escape hatch: if the terms of your prenup are so one-sided that they shock the conscience — and you didn’t understand the totality of your partner’s finances — the court can refuse to enforce it. Maybe your spouse-to-be had millions in assets but handed you a two-page agreement with zero financial disclosure. If the deal was grossly unfair and they kept you in the dark, that’s a problem.
A caution: unconscionability alone won’t kill the agreement. The party challenging it must also show they didn’t get fair disclosure, didn’t waive disclosure in writing, and couldn’t reasonably have known what their partner owned. If you had actual knowledge, even without formal disclosure, the unconscionability argument falls apart.
Don’t sign anything that seems unfair.
Spousal Support Waivers Get Extra Scrutiny
Think you locked in a waiver of spousal support? Not necessarily. California treats spousal support provisions with special care because it’s one of only nine community property states in the country. A waiver of spousal support is unenforceable if the person waiving support didn’t have independent legal counsel when they signed, or if the waiver is unconscionable at the time of enforcement (not just when signed).
So even if the prenup seemed fair on your wedding day, if circumstances change dramatically during the marriage (one spouse becomes disabled, the economy tanks, someone sacrifices their career), a court can refuse to enforce a support waiver that leaves one party destitute. California won’t allow prenups to create public charges or grossly unfair outcomes years down the road.
The Stuff You Can’t Contract Away
Some things are simply off-limits, no matter what your prenup says. California law is clear: you can’t contract away a child’s right to support. Any clause that tries to waive, limit, or predetermine child support is void, period. Courts calculate child support based on state guidelines and the parents’ actual circumstances at the time of divorce, and no prenup can override that.
Similarly, you can’t use a prenup to dictate child custody arrangements. Custody is always based on the best interests of the child at the time of the dispute, not what seemed like a good idea when you were engaged. California cares about the kids more than it cares about your financial goals, believe that.
What About Infidelity Clauses?
California is a No Fault state, which means it doesn’t matter who did it or why. If someone on social media claims you should include a prenup clause of liquidated damages for infidelity, know that these are unenforceable in California and void as a matter of public policy. In other words, California doesn’t care about sexual infidelity or marital misconduct.
This is not to say that your judge won’t care; a judge may want to know how or why the marriage broke down, but it is technically irrelevant to the outcome of your case, and has absolutely no place in a prenuptial agreement.
Can You Fix a Bad Prenup After the Fact?
What if you signed a flawed prenup and later tried to “ratify” it, maybe by referencing it in a trust amendment or living under its terms for years? Nope – California courts have held that premarital agreements that fail to meet the legal requirements are void, not just voidable. You can’t breathe life into an involuntarily executed agreement through later conduct or acceptance, so don’t embarrass yourself by trying.
The Bottom Line
If you signed a prenup years ago and you’re now facing divorce, don’t assume it’s airtight. And if you’re drafting one today, follow the rules:
- full disclosure
- independent counsel
- adequate time to review, and
- terms that won’t look unconscionable down the road.
Because in California, a signed prenup can be a golden parachute. But it’s not a bulletproof vest. If you have questions about prenuptial agreements or other California family law matters, the attorneys at Butler Law, PC can help you understand how California law may apply to your circumstances.