Unmarried couples who move in together often assume the law will treat them fairly if the relationship ends, but California offers almost none of the automatic protections spouses receive, which is exactly what a cohabitation agreement is designed to fix.
Key Takeaways:
- California does not recognize common law marriage, which means unmarried partners have no automatic right to property division or support when a relationship ends, regardless of how long the couple lived together.
- A cohabitation agreement is a legally enforceable contract that lets unmarried partners define ownership, financial responsibilities, and what happens to shared property if they separate.
- Our team helps couples build agreements that reflect the real financial picture of their relationship, protecting both partners rather than just the one who owns more.
Moving in with a partner is one of the biggest steps a relationship can take, and it usually happens without either person thinking much about the legal side of things. That is understandable. Nobody wants to open a conversation about a home, a joint account, or a shared business by planning for a breakup. But the couples who end up in the most difficult position are often the ones who assumed the law would sort things out fairly if the relationship ended, only to discover that California treats unmarried partners very differently from spouses.
Our team at The Grey Legal Group has spent years helping California families navigate the financial realities of relationships, both inside and outside of marriage. We understand how quickly a cohabiting relationship can become financially intertwined, and we know what it takes to build an agreement that actually protects both people if things do not go as planned. This post walks through what a cohabitation agreement can do, what it cannot do, and why more unmarried couples in California are choosing to put one in place.
WHY CALIFORNIA LAW LEAVES UNMARRIED COUPLES UNPROTECTED
California abolished common law marriage decades ago, and the state does not recognize it in any form today. This means that no matter how long a couple lives together, how they present themselves publicly, or how intertwined their finances become, the law does not automatically treat them as spouses. There is no community property presumption, no automatic right to support, and no built-in framework for dividing property when the relationship ends.
This gap became widely known after the California Supreme Court’s decision in Marvin v. Marvin, which established that unmarried partners can still enforce agreements, whether written, oral, or implied through conduct, regarding property and financial support. That ruling opened the door for cohabitation agreements, but it also underscored just how much unmarried couples are left to sort out on their own without one.
WHAT A COHABITATION AGREEMENT CAN ACTUALLY COVER
A cohabitation agreement lets partners define, in writing, how they want their finances and property handled both during the relationship and if it ends. This can include how a jointly purchased home will be divided, whether one partner is entitled to reimbursement for contributions made toward property titled in the other partner’s name, how shared bank accounts and household expenses will be managed, and how debts taken on during the relationship will be allocated if the couple separates.
The agreement can also address financial support between partners if one person significantly reduced their income or career growth to support the household or the other partner’s career, a situation that has no automatic legal remedy for unmarried couples the way spousal support does for married ones. For couples where one partner owns a business, the agreement can also clarify that business interests remain separate property regardless of the other partner’s involvement in the household.
WHAT THIS KIND OF AGREEMENT CANNOT DO
A cohabitation agreement cannot establish custody or child support terms for any children the couple has together, since California courts retain full authority over those decisions and apply the same best interest standard regardless of the parents’ relationship status. It also cannot create the same automatic rights a marriage provides in areas like retirement benefits, health insurance, or certain government protections, since those are tied specifically to legal marital status under state and federal law.
This is one of the most important distinctions between a cohabitation agreement and a prenuptial agreement, which modifies rights that already exist because of marriage. A cohabitation agreement instead creates rights and protections that would not exist between unmarried partners at all without the agreement in place.
SITUATIONS WHERE A COHABITATION AGREEMENT MAKES THE MOST DIFFERENCE
Couples who buy a home together but title it in only one person’s name for financing reasons often benefit the most from a clear agreement establishing how equity will be divided. The same is true for couples with a significant income gap, where one partner may have reduced work hours or stepped back from a career to support the household.
Blended families also benefit, particularly when one or both partners have children from a previous relationship and want to keep certain assets protected for those children regardless of what happens in the current relationship. Business owners who are cohabiting with a partner should also consider an agreement, since without one, contributions made by a partner, whether financial or through unpaid labor, can create ambiguity about ownership down the road.
BUILDING AN AGREEMENT THAT WILL ACTUALLY HOLD UP
A cohabitation agreement is far more likely to be enforced if both partners enter into it voluntarily, with full and honest disclosure of their finances, and ideally with independent legal review on both sides. Courts are more skeptical of agreements signed under pressure or without a clear understanding of what each partner is giving up or gaining.
Because these agreements deal with property law rather than family law statutes specific to marriage, drafting one that will hold up requires careful attention to contract principles alongside an understanding of how California courts have historically treated disputes between unmarried partners. A generic template rarely accounts for the specific financial picture two partners actually bring into a relationship.
Protecting yourself financially does not require distrust of your partner. It requires the same clarity any two people benefit from when they combine their lives and their finances. Our team at The Grey Legal Group brings 75+ years of combined family law experience helping California couples, married or not, put real protections in place. Schedule a complimentary initial consultation with a member of our team, and let us help you build an agreement that reflects the relationship you actually have.
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