For a couple in San Diego County, the place to start is figuring out which side of the agreement each partner is on. One partner may be proposing it, the other may be reviewing a draft, or the couple may already be married. California law sets the rules for each situation. A prenup must be in writing, signed by both partners, and signed voluntarily.
Most people facing a prenup are planning a wedding. They are also holding a conversation about money that can feel at odds with the occasion. One partner may own a home, a business or retirement savings from before the relationship. One may be entering a second marriage, or may have just been handed a draft and is unsure what it means. The basic question is the same in each case: what does a California marital agreement actually do, and which step comes first?
What a Premarital Agreement Does Under California Law
California's rules for prenups are in the Uniform Premarital Agreement Act, Family Code sections 1600 through 1617. Under Family Code section 1610, a premarital agreement is "an agreement between prospective spouses made in contemplation of marriage and to be effective upon marriage." Put simply, it is a contract two people sign before they marry. It has no effect until the wedding. Family Code section 1613 confirms that "a premarital agreement becomes effective upon marriage." From here on, this guide uses "prenup" or "agreement."
A prenup can change the property rules California would otherwise apply. Family Code section 1500 says the property rights of spouses "may be altered by a premarital agreement or other marital property agreement." Family Code section 1612(a) lists what the partners may contract about:
- each partner's rights and obligations in property, "whenever and wherever acquired or located"
- the right to buy, sell, use, transfer, mortgage, manage and control property
- what happens to property "upon separation, marital dissolution, death, or the occurrence or nonoccurrence of any other event"
- making a will, trust or other arrangement to carry out the agreement
- the death benefit from a life insurance policy
- which state's law governs how the agreement is read
- "any other matter, including their personal rights and obligations, not in violation of public policy or a statute imposing a criminal penalty"
"Property" is defined broadly. It includes income and earnings, and any interest that is present or future, vested or contingent (Family Code section 1610(b)). Debt is handled through the same provisions. Partners can agree on how financial obligations are treated during the marriage and how they are divided if it ends. Spousal support can also be addressed, but under stricter conditions covered in the next section.
The limits matter as much as the list. Section 1612(b) states that "the right of a child to support may not be adversely affected by a premarital agreement." Child custody is not among the subjects section 1612(a) lists. Nothing in an agreement may violate public policy or a criminal statute. A couple married in San Diego County signs an agreement governed by the California Family Code. If that agreement is ever tested, the test generally happens in the Superior Court of California, County of San Diego. More detail on how terms are written is on the prenup lawyer page.
California's Enforceability Requirements: What Makes a Prenup Valid
The first requirement is in Family Code section 1611: "A premarital agreement shall be in writing and signed by both parties. It is enforceable without consideration." An oral promise does not count. "Consideration" means something given in exchange, and section 1611 makes clear the agreement does not need it.
The central test is Family Code section 1615. An agreement is not enforceable if the partner resisting it proves either of the following:
- that partner did not sign voluntarily, or
- the agreement was unconscionable when signed, meaning it was so one-sided that it shocks fairness, and, before signing, all three of these were true for that partner:
- the partner did not receive "a fair, reasonable, and full disclosure" of the other partner's property or financial obligations
- the partner did not voluntarily and expressly waive, in writing, any right to further disclosure
- the partner did not have, and could not reasonably have had, adequate knowledge of the other's finances
Section 1615(b) leaves unconscionability for the judge to decide "as a matter of law."
Voluntariness has its own checklist. Under section 1615(c), an agreement "shall be deemed" involuntary unless the court finds, in writing or on the record, each of the following:
- Independent counsel. The partner had their own lawyer at signing. Alternatively, after being advised to get one, the partner waived that right in a separate writing. That advisement must come "at least seven calendar days before the final agreement is signed."
- Seven days with the final draft. For agreements signed on or after January 1, 2020, the partner must have had at least seven calendar days between first receiving the final agreement and signing it, "regardless of whether the party is represented by legal counsel." Agreements signed between 2002 and 2020 followed a slightly different version of this rule. Changes that are only nonsubstantive, meaning they do not alter the terms, do not restart the clock.
- Written explanation for an unrepresented partner. A partner signing without a lawyer must be fully informed, in writing, of the terms and the rights being given up. That partner must be proficient in the language used. The partner must also sign a document confirming the information was received and naming who provided it.
- No duress, fraud or undue influence, and no lack of capacity.
- Any other factors the court deems relevant.
Spousal support has a separate rule. Under section 1612(c), a spousal support provision, including a waiver, "is not enforceable if the party against whom enforcement of the spousal support provision is sought was not represented by independent counsel at the time the agreement containing the provision was signed." It is also unenforceable if the provision is "unconscionable at the time of enforcement." Having a lawyer does not rescue a provision that fails for another reason.
Read together, these sections lead to a practical conclusion. When each partner has a separate, independent attorney, the agreement meets section 1615's counsel requirement and section 1612(c)'s spousal support condition most directly.
Prenup Lawyer: Drafting and Reviewing California Premarital Agreements
The prenup lawyer page covers the whole process of a California premarital agreement. It runs from the first conversation about terms, through drafting, disclosure and the seven-day window, to signing. For most San Diego County couples starting from scratch, this is the first stop.
Independent Review of a Prenup You Were Handed
Being given a finished draft by a partner's attorney is a different position from writing one. The prenup review page is for the partner on the receiving end. It explains what independent review covers when the other side's lawyer prepared the document.
Drafting and Negotiating a Prenup With Separate Counsel
The prenup drafting page is written for the partner proposing the agreement. It covers preparing the terms, assembling the financial disclosure section 1615(a)(2) contemplates, and negotiating revisions.
Postnuptial Agreements in California: Drafting, Review and Enforcement
A couple who is already married is no longer making a premarital agreement. The Uniform Premarital Agreement Act is written for agreements made "in contemplation of marriage." The postnuptial agreement page covers drafting, reviewing and enforcing an agreement made after the wedding. Section 1500 permits that kind of agreement as an "other marital property agreement."
Enforcing a Prenup When a California Divorce Starts
Raising a prenup in a divorce is a litigation step, not a drafting step. The prenup enforcement page covers how a signed agreement's terms are put before the court once a divorce petition is filed in San Diego County. In the Superior Court of California, County of San Diego, that filing goes to one of four family law divisions (Central, North County, East County or South County), assigned by ZIP code under the court's ADM-254 list.
Challenging a Prenup: The Grounds California Allows
A challenge is the opposite of enforcement. It is the position of the spouse arguing that the agreement should not bind them. The challenge page explains the grounds under section 1615, already described above. Those grounds are involuntary signing, including the failed independent-counsel, seven-day and written-explanation conditions in section 1615(c), and unconscionability at signing combined with inadequate disclosure. For spousal support terms, section 1612(c) adds lack of independent counsel and unconscionability at the time of enforcement.
