Prenup vs. Postnup in California: Which One Makes Sense for You?
If you are getting married, already married, or experiencing a major financial or life change, you may be considering whether a prenuptial (premarital) agreement or a postnuptial (postmarital) agreement is the right choice under California law. While both agreements can protect assets and clarify financial expectations, they operate very differently and are treated differently by California courts.
This guide explains the differences between prenups and postnups, how California community property law affects them, and how to determine which agreement makes sense for your situation.
The Short Answer
In California, a prenuptial agreement is signed before marriage and is generally easier to enforce if it complies with statutory requirements. A postnuptial agreement is signed after marriage and is subject to heightened scrutiny because spouses owe each other fiduciary duties. If you are not yet married, a prenup is typically the stronger option. If you are already married, a postnup may still be appropriate but must be drafted with greater care.
Why California Community Property Law Matters
California is a community property state. Without a valid agreement, most income and assets acquired during marriage are presumed to be owned equally by both spouses, regardless of who earned the money or whose name is on the account. This default rule often surprises couples, particularly when there is a large income disparity, a business involved, or significant premarital assets.
Prenuptial and postnuptial agreements allow couples to override these default rules. They can define what remains separate property, clarify how income and assets will be treated during the marriage, address spousal support within legal limits, and reduce uncertainty if the marriage ends due to separation, divorce, or death.
Prenuptial Agreements in California
A California prenuptial agreement is a written contract signed before marriage that sets out each party’s financial rights and obligations. Prenups are commonly used when one or both parties own a business, have substantial premarital assets, expect future inheritances, have children from a prior relationship, or simply want clarity and predictability around finances.
To be enforceable in California, a prenup must meet specific legal requirements. It must be in writing and signed by both parties. Each party must provide full and fair disclosure of assets, debts, and income. The agreement must be entered into voluntarily, without pressure or coercion. California also requires a minimum seven-day waiting period between the time a final draft is presented and the time the agreement is signed. If spousal support is limited or waived, each party must have independent legal counsel at the time of signing.
When properly drafted and executed, prenups are generally upheld by California courts and offer the strongest level of protection.
Postnuptial Agreements in California
A postnuptial agreement is signed after the parties are already married. It can address many of the same issues as a prenup, including property characterization, income, debt allocation, and spousal support. Postnups are often considered when circumstances change after marriage, such as one spouse starting a business, receiving an inheritance, leaving the workforce, or when the couple wants to reorganize finances for estate or tax planning purposes.
However, postnups face greater legal scrutiny in California. Once married, spouses owe each other fiduciary duties similar to those owed between business partners. This means each spouse must act with the highest good faith and fair dealing. As a result, courts closely examine whether there was complete disclosure, whether the agreement was fair at the time it was signed, and whether one spouse gained an unfair advantage over the other. Because of this heightened standard, postnuptial agreements must be drafted carefully and thoughtfully to reduce the risk of future challenges.
Key Differences Between Prenups and Postnups
The most important distinction is timing. Prenups are signed before marriage, while postnups are signed afterward. From an enforceability standpoint, prenups are generally stronger because fiduciary duties have not yet attached. Postnups, while still valid when properly drafted, are examined more closely for fairness and disclosure. California’s seven-day waiting period applies specifically to prenups, though allowing time for review is still considered best practice for postnups.
Which Agreement Is Right for You?
If you are engaged or planning to marry in California and want to protect assets or clarify financial expectations, a prenuptial agreement is usually the best option. It provides clarity from the outset and minimizes enforcement risk later.
If you are already married and did not sign a prenup, a postnuptial agreement may still be appropriate, especially if your financial situation has changed or you want to formalize how assets and income are treated going forward. The key is ensuring the agreement is fair, transparent, and properly structured under California law.
Common California Pitfalls
Many agreements fail because they are rushed, incomplete, or improperly drafted. Waiting until the last minute before a wedding, relying on online templates, failing to disclose assets fully, or including unenforceable personal or lifestyle provisions can all undermine an agreement. Another common misconception is assuming that a postnup is just as easy to enforce as a prenup, which is not the case in California.
A Note for California and San Diego Couples
In high-cost areas such as San Diego, Los Angeles, Orange County, and the Bay Area, issues like real estate equity, stock compensation, and business ownership make well-drafted agreements especially important. California courts do not simply rubber-stamp marital agreements, particularly postnuptial agreements, and careful planning is essential.
If you have the choice, a prenuptial agreement offers the clearest and strongest protection under California law. A postnuptial agreement can still be effective, but it requires heightened care, full transparency, and balanced terms. Choosing the right agreement depends on timing, circumstances, and long-term goals.
📞 Considering a prenup or postnup? Contact our office today to schedule a free consultation. Your dedicated Prenuptial & Postnuptial Agreement Attorney Serving Clients throughout San Diego and All of California.
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