A California roommate agreement is a private written contract between people sharing a rental that sets each person’s share of rent, deposits, utilities, and household rules. It sits alongside — not inside — the master lease with the landlord, and it is enforceable between roommates in small claims court without notarization. What it can say is bounded by two things: the terms of the master lease and California’s rules on deposits, rent increases, and evictions.
Read the Master Lease Before You Draft Anything
Pull out the lease and find the subletting clause. Under California Civil Code Section 1995.210, a lease can restrict or prohibit a tenant from subletting or transferring their interest in the unit. If the lease is silent on subletting, the tenant generally has an unrestricted right to bring in a roommate or subtenant.1California Legislative Information. California Code Civil Code CIV 1995.210 If it requires the landlord’s written consent, skipping that step can be treated as a lease violation and grounds for eviction.
Even when the landlord approves the new roommate, the person on the master lease stays fully responsible to the landlord for all the rent and any damage. A side agreement between roommates doesn’t change that. That is exactly why the roommate agreement matters: it creates an enforceable record between co-occupants so the person stuck covering someone else’s share has a path to recover the money.
Know Which Kind of Roommate You Are
How much legal protection a roommate has depends almost entirely on which category applies, and the agreement should identify it on page one.
- Co-tenants all signed the master lease with the landlord. Each has an independent right to occupy the unit, and no co-tenant can evict another. Only the landlord can.
- Subtenants rent from a master tenant rather than the landlord. The master tenant acts as the subtenant’s landlord for practical purposes and can bring an eviction against the subtenant.
- Lodgers rent a room in a home where the owner personally lives and keeps access to the whole dwelling. California limits this category to situations where a single lodger lives with the owner.2California Legislative Information. California Code CIV 1946.5
The lodger rule carries the biggest surprise. When a single lodger’s tenancy ends after proper written notice, the lodger has no right to remain, and the owner can have the lodger removed as a trespasser without filing a formal eviction lawsuit.3California Legislative Information. California Code Civil Code CIV 1946.5 That is far weaker than a subtenant or co-tenant, who can only be removed through the court eviction process. If you’re renting a room from someone who owns and lives in the home, this is the section of law that governs you.4California Courts. If You Rent a Room Out (Lodgers)
Joint and Several Liability on a Shared Lease
Co-tenants who sign the same lease share something most people don’t learn about until it costs them. Under joint and several liability, every co-tenant is independently responsible for the full rent, not just their share. If one roommate stops paying, the landlord does not have to chase down the person who skipped. The landlord can demand the whole balance from whichever remaining tenant is easiest to collect from.
A roommate agreement cannot change that obligation to the landlord. What it can do is give you ammunition against the roommate who left you holding the bag. California allows individuals to sue for up to $12,500 in small claims.5California Courts. Small Claims in California Without a written agreement, you’re trying to prove the terms of a verbal deal, which is harder and less predictable.
What to Put in the Agreement
A roommate agreement works best when it covers the dull details nobody wants to discuss until there’s a problem. Start with the full legal names of every occupant, the property address, and the date the arrangement starts.
Rent, Due Dates, and Late Fees
Spell out the exact dollar amount each person pays and when it’s due. If one bedroom is larger, the split should reflect that. Say who collects the money and submits it to the landlord, and what happens if someone pays late. A built-in late fee between roommates, say $25 per day after a three-day grace period, creates a real incentive to pay on time.
Utilities
List every account — electricity, gas, water, internet, trash — and whose name is on each one. Even when a bill is in only one person’s name, the other roommate can still be held liable for their agreed share, because courts look at the conduct between the parties and the history of payments, not just whose name appears on the account. A written split removes the guesswork.
House Rules and Guests
Quiet hours, cleaning rotations for shared spaces, and rules about smoking or pets belong in the agreement because they’re the issues most likely to escalate. Overnight guests deserve their own clause. Many agreements cap overnight stays at a set number of consecutive nights, which helps prevent a guest from gradually becoming an unauthorized occupant. Under many California leases, an undisclosed long-term guest can violate the master lease and put the whole tenancy at risk.
Shared Property
If roommates split the cost of furniture, kitchen gear, or a television, write down who owns what and how the value gets handled when someone moves out. A short inventory with approximate values prevents arguments later. Note how running shared costs like cleaning supplies get tracked.
Move-Out Notice
The agreement should say how much notice a departing roommate must give and whether they’re responsible for finding a replacement. Without this, a roommate on a month-to-month arrangement can leave with minimal warning and stick the remaining occupants with a share they may not be able to cover.
Security Deposit Rules You Can’t Contract Around
California Civil Code Section 1950.5 sets strict deposit limits. Since July 1, 2024, landlords can charge no more than one month’s rent as a security deposit for residential units, regardless of whether the unit is furnished.6California Legislative Information. California Code CIV 1950.5 There is a narrow exception: landlords who are natural persons (or LLCs made up entirely of natural persons) and own no more than two rental properties with a combined four or fewer units can still charge up to two months’ rent.7California Department of Justice. Know Your Rights as a California Tenant Security Deposits These same rules apply when a master tenant collects a deposit from a subtenant. A clause requiring three months’ rent as deposit would be void regardless of what both roommates signed.
Address how the deposit is divided among roommates. If one person paid the whole deposit and someone new moves in later, say whether the incoming roommate reimburses a proportional share upfront and how any refund gets split at the end.
Getting the Deposit Back
When a tenant vacates, the landlord has 21 calendar days to either return the full deposit or provide an itemized statement explaining every deduction. Deductions can only cover unpaid rent, cleaning to restore the unit to its move-in condition, and repairing damage beyond normal wear and tear.8California Courts. Guide to Security Deposits in California If the total deductions exceed $125, the landlord must attach copies of receipts or invoices.7California Department of Justice. Know Your Rights as a California Tenant Security Deposits A landlord who withholds a deposit in bad faith can be ordered to pay up to twice the deposit amount in statutory damages on top of the tenant’s actual losses.6California Legislative Information. California Code CIV 1950.5 A master tenant collecting a deposit from a subtenant steps into the landlord’s shoes and must follow the same timelines and documentation.
Tenants have the right to request an initial inspection before the tenancy ends. During the walk-through, the landlord identifies conditions that could lead to deductions, giving the tenant a chance to clean or repair before the final accounting. The inspection cannot be scheduled earlier than two weeks before move-out.9California Legislative Information. California Civil Code 1950.5 It is one of the most underused protections in California tenant law. Take your own dated photos at move-in and move-out, too — those images become powerful evidence in any deposit dispute.
If You’re a Master Tenant Subletting, AB 1482 Applies to You
The Tenant Protection Act of 2019 (AB 1482) caps annual rent increases and requires landlords to have a valid reason — called just cause — before evicting a tenant who has lived in the unit for at least 12 months.10California Legislative Information. California Code AB 1482 Tenant Protection Act of 2019 The cap limits increases to 5% plus the local Consumer Price Index change, or 10% total, whichever is lower, within any 12-month period. Just cause includes reasons like nonpayment of rent, breach of the lease, or the landlord’s intent to occupy the unit.
A master tenant who charges rent to a subtenant is bound by these same caps. The total rent collected from all subtenants cannot exceed the rent the master tenant pays to the landlord.11Contra Costa Housing Authority. AB 1482 The California Tenant Protection Act of 2019 Not every rental falls under AB 1482 — common exemptions include units built within the last 15 years, owner-occupied duplexes, and single-family homes or condos where the owner isn’t a corporation and gave the tenant a specific written exemption notice. AB 1482 is currently set to expire on January 1, 2030.
Ending a month-to-month tenancy requires written notice. If the tenant has lived in the unit for less than one year, 30 days’ notice is required. If the tenant has been there one year or more, the notice period extends to 60 days.12California Courts. Types of Eviction Notices Tenants Master tenants evicting subtenants have to follow these same timelines.
When a Roommate Leaves Stuff Behind
When a roommate moves out and leaves belongings, California law requires written notice before the property can be disposed of. The notice must describe the items, explain where and how the former occupant can claim them, and set a deadline — at least 15 days if the notice is personally delivered, or 18 days if mailed.13California Legislative Information. California Civil Code 1984 If the property appears to be worth less than $700, it can be kept, sold, or destroyed after the notice period expires. More valuable items must be sold at a public sale. Throwing everything out the day after someone leaves is a quick way to end up liable for the value of those belongings.
Signing, Resolving Disputes, and Enforcement
All roommates should sign and date the agreement on the same day, using the names on their government identification. Notarization isn’t required — a signed agreement between competent adults is a valid contract under California law. Everyone keeps a copy. If terms ever change (new rent split, new roommate, updated guest policy), everyone signs and dates an amendment and attaches it to the original.
A dispute clause saves money. The simplest version says roommates will try to resolve disagreements through direct conversation first, then mediation with a neutral third party, before anyone files in small claims court. Community mediation services exist throughout California, often at little or no cost.
If mediation fails, small claims court is the typical venue for roommate disputes, and the $12,500 limit covers most unpaid-rent and deposit fights.5California Courts. Small Claims in California The agreement itself becomes the central piece of evidence. Judges look for a clear written record of who agreed to pay what, and when. Verbal agreements are enforceable in California, but proving their terms is an uphill fight compared to handing a judge a signed document.
One last check before signing: compare every financial term in the roommate agreement against the master lease and the statutory limits above. Any clause that conflicts with either is void, no matter who signed it.