Who Gets What? Understanding Partition Actions for Co-Owned Property in California

Who Gets What? Understanding Partition Actions for Co-Owned Property in California

Heela Nasiri-Bakhtani

It has become increasingly common for unmarried co-owners to hold property together as joint tenants — whether as partners, family members, or investors. The burning question is what happens when the co-ownership arrangement ends, but the property deed doesn’t? A 50-50 split of the proceeds may seem like the obvious answer, but the reality is often more complicated. It’s worth noting that partition actions generally apply to unmarried co-owners; divorcing spouses typically divide property through the separate process governed by California’s Family Code, rather than through a partition action.

What is a Deed?

A deed is a legal document that officially transfers ownership of real property from one person to another. It spells out who owns the property and how parties own it together. One of the most common ways co-owners hold title is by holding title as joint tenants. A joint tenancy is a way for 2 or more parties to co-own property in equal shares, with a right of survivorship. This means when one owner passes away, their share automatically goes to the surviving owner(s).

What Happens to the Property in a Partition Action?

A partition is a legal action that allows a co-owner of a property to ask a court to divide or sell the property when the owners can no longer agree on what to do with it. When California courts decide to sell the property and divide the proceeds, division isn’t a simple 50/50 split. This is where courts must conduct an accounting, a process used to determine who paid what over the years and to adjust the division of proceeds.

Once co-owners decide to end their arrangement and sell the property, the question becomes who gets what? Owning equal shares of property in a joint tenancy seems straightforward: each party receives 50%. But, things get less straightforward when certain parties invest a greater amount of their earnings into the property. For example, one party may make the full initial down payment on the property, or they may pay the mortgage, property taxes, insurance, and property investments while the other party invests nothing and doesn’t even live on the property. When the parties decide to sell or divide the property, “equal shares” wouldn’t seem fair. This is where the court analyzes the facts to determine a division of the property that reflects what each person actually contributed to it over the years.

Can I get credit for the mortgage, property taxes, and/or insurance payments I made while co-owning property?

The good news is that California courts often use accounting to credit the co-owner who contributed more than their share toward the mortgage, property taxes, and/or insurance payments. When a co-owner pays more than their fair share of the property fees, they do so to protect the property for both owners and to avoid detrimental consequences, such as foreclosure. The courts often recognize this and understand that if the house payments were not made, everyone’s stake in the property could be wiped out, not just the individual who missed a payment. The court views this contribution as one that should be credited back, not a favor that gets forgotten.

Yet, what if the co-owner who paid over 50% of house payments was the only one living in the property, whereas the other didn’t? Would the court still consider this a benefit to both? The co-owner who didn’t live on the property can argue that the paying party received all the benefits. This is where the court may offset some of the mortgage, tax, or insurance credit against the fair rental value of the exclusive use by one co-owner, asking whether it is fair to fully reimburse someone who also benefited from living there rent-free.

This offset is not automatic. To trigger it, a court generally looks for either an actual ouster — meaning the non-occupying co-owner was physically excluded or prevented from using the property — or a clear demand by the non-occupying co-owner to share or use the property that was refused by the occupying co-owner. The offset does not apply simply because one co-owner voluntarily chose to move out or live elsewhere.

Alternatively, if neither co-owner used the property, courts often won’t apply this offset, since no party would be found to be denied access to the property.

In short, being the only co-owner who uses or lives in the property doesn’t preclude their reimbursement claim, but it can be a factor the court weighs, depending on how and why the other co-owner ended up not living there.

Can I get credit for initial investments, such as down payments?

Down payments and upfront investments work differently from ongoing payments like mortgages or taxes. The courts often look at why the property was titled the way it was.

If both owners contributed to the down payment and took title together from the start, courts often treat that as reflecting the parties’ intent to own the property, even if contributions weren’t equal.

But if one person purchased the property on their own first and only later added the other person to the title, things shift. Adding someone to a deed without receiving anything in return can look like a gift of equity, and once such a gift is complete, it generally cannot be undone simply because the relationship ends. But if there is evidence that adding a party to the deed was NOT an outright gift, such as for a practical reason unrelated to giving away ownership, a court may be more willing to consider reimbursement.

This turns heavily on the specific facts and evidence of the case, including what the deed says, when it was signed, and what each person intended at the time. This is an area where it’s especially important to talk to an attorney before assuming how a down payment will be treated.

Can I be reimbursed for the investments I made in the property and the renovations I made while co-owning it?

Parties may be reimbursed for renovations and investments made to improve the property, but not for the full dollar amount spent. Instead, in California courts, the courts look at how much the improvement increased the property’s value by the time of partition.

For example, if you put $50,000 into a renovation but it only added $20,000 to the property’s value, the reimbursement is generally tied to the $20,000 increase, not the amount originally spent. The court will look at whether the work done was undertaken in good faith to improve or maintain the property, rather than to reflect personal preferences. One important limitation: courts do not credit the value of a co-owner’s own personal labor. Reimbursement is limited to the cost of materials and any third-party labor actually paid out of pocket — you cannot bill for your own time.

Because this value-added analysis often requires evidence, such as appraisals, before-and-after comparisons, or contractor invoices, documentation matters a lot here. The better records you keep, the easier it is to support a reimbursement claim down the line. An experienced attorney can help you figure out what evidence will actually hold up in court and how to put together the strongest case for the contributions you made.

Why is accounting vital before you sell your property?

Selling a co-owned property may seem simple. List it, sell it, and split the proceeds 50-50. We have covered how an even split does not always reflect what each person has actually contributed to the property over the years. Without an accounting, a co-owner who covered more than their share of the mortgage, taxes, insurance, or improvements could end up walking away with far less than what they contributed. This is why we are here to help.

An accounting gives both parties a chance to lay out exactly what they contributed, and gives the court a way to adjust the final numbers, rather than defaulting to a 50-50 division. Skipping this step, or assuming it will sort itself out informally between co-owners, can mean leaving money on the table that you’d otherwise be entitled to recover.

Before listing a co-owned property for sale, especially one with a complicated history of contributions, it’s worth talking to an attorney to understand what you may be owed before any sale moves forward.

Navigating a partition action can be complicated, especially when years of contributions are at stake. Tierney Law Group’s Pleasanton-based attorneys are here to help you understand your rights and pursue a fair outcome. Contact us today to schedule a consultation.