Premarital and Postnuptial Agreements in California: Drafting for Enforceability

A premarital agreement that fails enforceability review becomes exhibit one in the litigation it was supposed to prevent. For family law practitioners, prenup drafting in California is as much a litigation-avoidance exercise as it is a transactional one. The statutory requirements under Family Code 1615 and the broader UPAA California enforceability framework are specific, and courts enforce them strictly.

Voluntariness, financial disclosure, independent counsel, and the seven-day waiting period are the grounds on which agreements get thrown out. The statutory framework for California premarital agreement requirements, the enforceability challenges courts most often sustain, the elevated standard for postnuptial agreements, and a drafting checklist all shape whether an agreement holds up or ends up in litigation.

Meeting California’s Statutory Requirements for Enforceable Premarital Agreements

Under the Uniform Premarital Agreement Act, codified beginning at Family Code § 1610, an agreement must be in writing and signed by both parties. What generates litigation is what happens around the signing. For example, the conditions under which consent was obtained, the adequacy of financial disclosure, and whether the formalities required by Family Code § 1615 were satisfied. The following are the requirements practitioners most often handle incorrectly.

• Voluntariness means the agreement was not the product of duress, fraud, or undue influence.
•  Financial disclosure requires a fair and reasonable disclosure of each party’s assets and obligations that will satisfy UPAA California enforceability standards.
• Under AB 1380, effective January 1, 2020, the seven-day waiting period applies to every premarital agreement, regardless of whether either party has independent counsel. The agreement cannot be signed until at least seven calendar days after the final version was first presented for review. Represented parties no longer have the option to negotiate terms up to the moment of signing.

These requirements form the foundation of an enforceable agreement, but they are only part of the analysis. Each agreement should also be evaluated in light of the governing statutes and current California case law. CEB’s Family Law resources provide additional analysis and practical guidance for attorneys drafting and reviewing premarital and postnuptial agreements.

Enforceability Pitfalls That Most Often Lead to Litigation

Most premarital agreement challenges in California turn on inadequate disclosure, pressure surrounding execution, and spousal support provisions that courts deem unconscionable or procedurally defective. Unconscionability at the time of signing is a distinct ground for challenge under Family Code 1615.

A court evaluating this claim looks at both the procedural circumstances of execution and the substantive fairness of the terms. An agreement that was signed under time pressure, without access to counsel, or with materially incomplete disclosure is vulnerable on procedural grounds regardless of how balanced the substantive terms appear.

Under Family Code § 1612(c), a provision waiving or limiting spousal support is unenforceable if the party against whom it is sought wasn’t represented by independent counsel during signing, or if the provision is unconscionable at the time of enforcement.

Courts have declined to enforce support waivers where one party would be left without any means of support as a direct result. Draft these provisions with the long view in mind, not just the circumstances at the time of signing.

Drafting Postnuptial Agreements Under California’s Heightened Fiduciary Standard

A postnuptial agreement in California operates under a fundamentally different legal standard than a premarital agreement. Because the parties are already married when they execute it, Family Code § 721 imposes a fiduciary duty on each spouse toward the other. That duty requires good faith and fair dealing beyond the ordinary contractual standard.

The following table highlights the key distinctions between premarital and postnuptial agreements that shape your drafting approach.

When drafting a postnuptial agreement in California, document the disclosure process thoroughly, ensure both parties have independent counsel, and avoid provisions that create a substantial imbalance without a clear, documented rationale. For more detailed discussion of drafting considerations, disclosure obligations, and enforceability issues in family law agreements, read the California Marital Settlement and Other Family Law Agreements.

Practical Drafting Checklist: Avoiding the Mistakes That Undermine Enforceability

The enforceability of a premarital or postnuptial agreement is determined largely by what happens before the parties sign. You need a definitive checklist that provides a structured final review before execution to avoid litigation issues in prenup drafting in California matters.

1. Confirm that financial disclosures are complete and accurate: Attach a schedule of assets and liabilities for each party, and verify the figures against current statements before the agreement is signed.
2. Verify the seven-day waiting period has been satisfied: Document the date the final draft was presented and confirm the signing date falls at least seven calendar days later, regardless of whether either party has independent counsel.
3. Confirm independent counsel for both parties: Document each party’s representation in the agreement itself and retain signed acknowledgments.
4. Review spousal support provisions under § 1612(c): Assess both current unconscionability and potential unconscionability at enforcement given foreseeable life changes.
5. For postnuptial agreements, document the disclosure process separately: The fiduciary duty standard requires evidence that full disclosure occurred and that neither party was under pressure at signing.
6.  Review execution formalities: Confirm signatures, notarization where required, and that each party received a fully executed copy at signing.

Having a practical drafting checklist distinguishes between an agreement that holds up and one that gives the opposing party a roadmap. The statutory requirements under Family Code 1615 are unforgiving, and the fiduciary standard governing postnuptial agreement California matters only raises the bar further. Every provision you include is either evidence of a careful, compliant process or an opening for a challenge.

Our Family Law Hub provides California premarital agreement requirements checklists, sample provisions, and current case law on enforceability under Family Code 1615 and the UPAA California enforceability framework. Explore the Family Law Hub at CEB.com.