Partition Actions Between Unmarried Couples in California: Joint Tenancy Disputes

Buying a house with a partner is a massive financial commitment. However, when an unmarried couple in California breaks up, splitting real estate is far more complicated than it is for married couples. Married couples divide property through family court under community property laws. Unmarried couples, on the other hand, do not have this luxury. Whether you own a condo in San Francisco or a suburban home in Orange County, if your ex refuses to sell or buy out your share, your only legal remedy is to file a civil lawsuit known as a partition action. This guide will walk you through California property laws, how to resolve unequal financial contributions, and how finding the right lawyer from our US Lawyers directory can protect your equity.

Joint Tenancy vs. Tenancy in Common under California Civil Code

The first step in any unmarried property dispute is examining your recorded deed. California law distinguishes co-ownership forms under the Civil Code, while judicial division of co-owned real property is governed by Cal. Civ. Proc. Code § 872.010 et seq..

Joint Tenancy: Codified under Cal. Civ. Code § 683, a joint tenancy requires equal shares with an automatic right of survivorship. However, you do not need a lawsuit to sever this arrangement. Under Cal. Civ. Code § 683.2, any co-owner has the absolute right to unilaterally sever a joint tenancy without the other partner's consent or court intervention simply by executing and recording a severance deed conveying the interest to themselves, converting the title into a tenancy in common.

Tenancy in Common: Governed by Cal. Civ. Code § 685 and Cal. Civ. Code § 686, tenancy in common is California's default co-ownership structure. Ownership percentages do not have to be equal (e.g., a 70/30 split), and there is no right of survivorship. When co-owners separate, the court assesses these percentage shares during partition proceedings, adjusting distributions through a final accounting of mortgage payments, property taxes, and necessary improvements.

Step-by-Step Process for Unmarried Couples in California

Navigating a partition action requires a strategic approach. Here is how the process works in local civil courts.

Step 1: Formal Buyout Offer

Before launching a lawsuit, your attorney should draft a formal buyout demand. This outlines the home's estimated equity and offers your ex the chance to refinance the property in their own name and pay you your 50% share in cash. This step avoids expensive court costs if they agree.

Step 2: Filing the Partition Lawsuit

If they ignore you or refuse to refinance, your attorney will prepare a formal complaint for partition drafted on pleading paper under Cal. Civ. Proc. Code § 872.210, filed alongside mandatory Judicial Council forms including Form CM-010, California, Judicial Council, Civil Case Cover Sheet and Form SUM-100, California, Judicial Council, Summons in the local civil court, such as the Superior Court of California, County of Los Angeles, Los Angeles or Superior Court of California, County of Riverside, Riverside. At this point, the family court has no jurisdiction; this is strictly a real estate business dispute.

Step 3: The Accounting Phase

This is the most critical step for unmarried couples. The judge will order an "accounting" of the property. If you paid the entire mortgage, property taxes, and a $20,000 roof repair out of your own pocket while your ex contributed nothing, your attorney will present these receipts to the judge. The judge can order "credits" to your side, meaning you get reimbursed from your ex's share of the final sale.

Step 4: Appraisal, Buyout Election, or Open-Market Sale

Under the California Partition of Real Property Act (Cal. Civ. Proc. Code § 874.311 et seq.), the court will first determine the property's fair market value through an independent appraisal under Cal. Civ. Proc. Code § 874.316. The non-petitioning co-owner is then given the statutory right to elect to buy out the other owner's interest at appraised value under Cal. Civ. Proc. Code § 874.317. If no party exercises this buyout right, the court orders an open-market sale through a licensed real estate broker under Cal. Civ. Proc. Code § 874.320, ensuring the home is sold at fair market value rather than a discounted auction.

Specific Disputes in California Real Estate

Modern relationships create complicated financial entanglements. Here is how California courts handle specific micro-niches in unmarried property disputes.

Tech Workers and RSUs

In the Bay Area, it is common for one partner to use vested Restricted Stock Units (RSUs) or a massive corporate bonus to fund a $200,000 down payment, while putting the home in joint tenancy with a partner who contributed nothing. In a partition action, tracing the source of those funds is vital. While joint tenancy implies a 50/50 gift, a skilled attorney can sometimes argue for reimbursement if there was a separate written agreement regarding the down payment.

Co-Signers Who Didn't Pay the Mortgage

Sometimes, one partner has bad credit, so the other partner puts the mortgage entirely in their own name, but both go on the title deed. If the relationship ends, the non-paying partner still legally owns 50% of the house. During the partition accounting, your lawyer will aggressively demand full reimbursement for every mortgage payment made by the sole borrower, severely reducing the non-paying ex's final payout.

Unequal Down Payments and Marvin Claims

In California, unmarried cohabitants can sometimes enforce verbal or implied contracts regarding property division, known as a "Marvin Claim" under the landmark California Supreme Court decision in Marvin v. Marvin, 18 Cal. 3d 660 (CA Supreme Court 1976). If you made a massive unequal down payment based on an oral promise that you would get it back when the house sold, your attorney might combine a Marvin Claim with the civil partition action to ensure the court honors that agreement.

How Much Does it Cost in California?

How Long Does the Process Take?

Because unmarried couples do not have to wait for a 6-month mandatory divorce cooling-off period, a civil partition can sometimes move faster. If your ex realizes they will lose the house and be forced to pay referee fees, they may agree to a settlement buyout in 3 to 5 months. If the case requires an intense forensic accounting fight over who paid for what over the last five years, it will likely proceed to a full trial, taking 12 to 18 months in California civil courts.

Frequently Asked Questions (FAQ)