Buying a home with a partner you are not married to in California? Learn why a cohabitation agreement protects you both, how title choices matter, and what happens without one.
You found the house. You love each other. You are splitting the down payment, sort of. One of you is putting in more, but you will figure that out later.
We need to talk about “later.”
Buying a home with someone you are not married to is incredibly common in California: couples on their own timeline, partners who never saw the point of marriage, LGBTQ+ couples and chosen family building lives on their own terms, and friends or siblings pooling resources to get a foot in an impossible market. It is also one of the riskiest legal situations we see. Not because anything is wrong with the relationship, but because unmarried co-owners have no built-in legal framework when things change. This post explains the gap, what a cohabitation agreement does about it, how your title choice fits in, and what happens to the people who skip both.
The Gap Nobody Mentions at the Open House
Marriage, whatever else you think of it, comes with a default legal operating system. Community property rules, family courts, structured processes for dividing assets and debts, spousal protections, automatic inheritance rights. You may never need any of it, but it is there, quietly running in the background, ready to sort things out if the relationship ends or one spouse dies.
Unmarried partners have none of that. If you break up, there is no family court process for dividing your home, and the law does not care who paid more of the down payment, who covered the mortgage during the year one of you was between jobs, or who spent every weekend for six months renovating the kitchen with their own hands. The law mostly cares about one document: the deed. And the deed almost never tells the full story of your actual financial arrangement, because the deed was filled out in thirty seconds during escrow by people who were thinking about paint colors, not breakups.
That gap, between what the deed says and what the two of you actually agreed to and contributed, is precisely where disputes are born. Two people remember the same arrangement completely differently once the relationship sours, and without a document, there is no referee but a judge.
What a Cohabitation Agreement Actually Does
A cohabitation agreement, sometimes called a property or co-ownership agreement, is a contract between unmarried partners that answers, in advance and in writing, the questions you would otherwise be fighting about mid-breakup. It is the operating system you build for yourselves because the law did not hand you one.
A good agreement covers who owns what percentage and why, especially when contributions are unequal. It addresses how the down payment is treated and whether an unequal down payment is a loan, a gift, or an ownership adjustment. It sets out how the mortgage, property taxes, insurance, maintenance, and major repairs get split month to month. It defines what happens if one person wants out, including whether the other has a right to buy them out, how the home gets valued, and on what timeline. It spells out what happens if you break up and neither wants to sell, and it addresses what happens if one of you dies.
It is not unromantic, and it is not a sign you expect to fail. It is the opposite. Writing this down while you like each other means the agreement is fair, calm, and mutual. Negotiating the same questions after a breakup means every clause is a battle and a lawyer is billing both of you by the hour. The agreement is a gift you give the two people you are right now to the two people you might become later.
Your Title Choice Carries Real Consequences
During escrow, someone, often the escrow officer, will ask how you want to hold title. Most unmarried buyers answer in thirty seconds with whatever sounds reasonable or whatever the form suggests. This decision deserves much more than thirty seconds, because the two main options lead to genuinely different places.
Joint tenancy means equal ownership with a right of survivorship. If one of you dies, the other automatically owns the entire property, immediately and outside of probate, no matter what either person’s will or trust says. That can be exactly what partners want, a clean automatic transfer to each other. But it has two catches: it forces equal ownership even when one person contributed far more, and the automatic survivorship overrides your estate plan, which can be a problem if either of you has children or other people you want to provide for.
Tenants in common lets you own in any percentages you choose, 50-50, 70-30, 80-20, whatever reflects reality. Each owner’s share passes through their own estate plan at death, not automatically to the co-owner. That flexibility is ideal for unequal contributions, but it carries its own catch: without an estate plan, a deceased owner’s share passes to their heirs under intestacy law, which means your surviving partner could suddenly co-own the home with your parents or siblings. Picture grieving and negotiating a buyout with your late partner’s family at the same time.
Notice that both options have a catch, and both catches are solved the same way: by pairing your title choice with a cohabitation agreement and an estate plan. Title, contract, and estate documents are three legs of one stool, and a stool with two legs falls over. The estate planning leg is especially important for unmarried and LGBTQ+ couples, and you can learn more about it on our estate planning services page.
What Happens Without an Agreement
When unmarried co-owners split with nothing in writing, the outcomes are ugly and predictable. The most common is a stalemate: one person wants to sell, the other refuses or cannot afford to buy them out, and meanwhile the mortgage payment arrives every month with both names on it and both credit scores on the line.
When the stalemate hardens, it becomes a partition action, a lawsuit asking the court to force the sale or division of the property. Partition works, in the sense that it ends the deadlock, but it is slow, public, and expensive, and the legal fees come out of the very equity the two of you spent years building. A forced sale rarely fetches top dollar, either. Everybody loses a little so that nobody has to keep losing.
Then there are contribution fights, where one person tries to prove, years after the fact, that they paid more, using a shoebox of bank statements and a deep well of resentment. And survivorship surprises, where one partner dies and the survivor discovers that the deed, the beneficiary forms, and the absent estate plan do not say what everyone always assumed they said. Every one of these is preventable with documents that cost a small fraction of what the disputes cost.
A Note for LGBTQ+ Couples and Chosen Family
Many LGBTQ+ couples choose not to marry, or marry on their own timeline, and some buy homes with chosen family rather than a romantic partner. Those choices are valid and increasingly common, and they deserve legal protection built on your terms rather than borrowed from assumptions designed for someone else’s family.
A cohabitation agreement, an intentional title vesting, and a set of estate documents together make sure the people you actually build a life with are the people the law actually protects. This matters even more where biological relatives might assert themselves at a vulnerable moment. The law does not know who your people are until you put it in writing, and once you do, the question is settled.
When to Put This in Place
Before you close. Ideally before you are even in escrow, while you still have room to make decisions calmly rather than under deadline pressure with a lender waiting. The agreement and the title choice should be made together, on purpose.
The second-best time is now, even if you already own the home together and never put anything in writing. An agreement signed after purchase is still vastly better than no agreement at all, and it is far easier to negotiate while the relationship is healthy than to reconstruct after it is not.
When to Get Help
At Your Home Legal, we help unmarried California buyers and co-owners get protected from the start, and we help current owners put protections in place after the fact. We draft cohabitation agreements, advise on the right way to hold title, prepare the deed correctly, and connect it all to an estate plan so the three legs of the stool actually hold. It is a natural part of our real estate services, and it works best handled together rather than piecemeal.
Buying a home with someone you are not married to, or already did and never put anything in writing? This is your moment to get protected.
Book a consult or send us a message. We will build a cohabitation agreement and title structure that fits your relationship, your finances, and your future.
