A California room rental agreement is a written contract between a homeowner (or primary tenant) and a single person renting one room in a shared residence, and it needs to reflect the state’s lodger rules, the one-month deposit cap, specific required disclosures, and clear house terms covering rent, utilities, guests, and shared spaces. Get those pieces right and the arrangement protects both sides; leave them vague and you are writing the script for a dispute.
Lodger or Tenant? Start Here
California Civil Code Section 1946.5 treats the person renting your room as a lodger only when three things are true at once: you own and live in the home, they are the only renter in the dwelling, and you keep the right to enter every area of the property, including their room.1California Legislative Information. California Code, Civil Code CIV 1946.5 – Hiring of a Room by a Lodger Rent to two or more people in the same home and no one in the house is a lodger under the statute; everyone becomes a standard tenant.
That classification matters most at the end. To close out a lodger arrangement, the owner gives written notice equal to the rent-payment interval, so 30 days for monthly rent. A lodger who stays past the notice period is a trespasser under Penal Code Section 602.3, and the owner can involve law enforcement rather than file a formal eviction.2California Legislative Information. California Penal Code 602.3 A standard eviction can take weeks or months. If there is any chance you will later rent a second room, know that doing so collapses the lodger framework for everyone in the house.
What the Agreement Should Say
Short is fine. Specific is not optional. At minimum, write down:
- The exact room being rented, named clearly enough that no one can argue about which space is private (for example, “the southeast upstairs bedroom”).
- Monthly rent, the day it is due, acceptable payment methods, and any grace period before a late fee applies.
- The deposit amount in dollars, confirming it fits the legal cap discussed below.
- Whether the arrangement is month-to-month or runs for a fixed term, and how either side ends it.
- Utilities: whether they are included, split as a flat monthly fee, or divided based on occupancy, and which utilities are covered.
House Rules and Shared Spaces
Kitchens, bathrooms, and living rooms are where friction shows up fastest. Set expectations in writing: cleaning responsibilities, noise hours, smoking policy, pets, assigned parking, storage, laundry access, and any appliance-use schedule you need. These feel small when everyone is still being polite. They are what people argue about three months in.
Guest Limits
An unauthorized occupant who stays long enough can acquire tenant rights, which undoes the lodger protections in Section 1946.5. California law generally treats someone who stays 14 days within a six-month period, or seven consecutive nights, as potentially crossing from guest to occupant. Pick a limit (for example, no more than three consecutive nights or ten per month) and require written permission for anything longer.
Late Fees
California does not fix a dollar cap on late rent fees, but the amount has to be reasonable and tied to the owner’s actual cost of a late payment. Most agreements land around 5% of monthly rent or a modest flat sum. Whatever you set, it has to appear in the written agreement before signing, and anything that reads as a penalty rather than a reasonable estimate will not hold up.
Security Deposit: The Number and the Deadline
Since July 1, 2024, Civil Code Section 1950.5 caps security deposits at one month’s rent for most residential rentals, furnished or not.3California Legislative Information. California Civil Code 1950.5 A narrow small-landlord exception lets individuals (or LLCs made up entirely of individuals) who own no more than two rental properties with a combined four units or fewer collect up to two months’ rent, but only when the prospective lodger is not a service member.4California Legislative Information. AB-12 Tenancy: Security Deposits Everyone else is at one month.
After the lodger moves out, the owner has 21 calendar days to return the deposit with an itemized statement of any deductions and backup (receipts, invoices, or a written description of work with time and hourly rate). If a repair cannot be finished inside that window, the owner can deduct a good-faith estimate and provide final documentation within 14 days of completing the work.3California Legislative Information. California Civil Code 1950.5 Holding a deposit in bad faith can trigger statutory damages of up to twice the deposit on top of actual damages. Take the deposit by check, electronic transfer, or money order so you have a trail.
Required Disclosures
Several disclosures have to be in writing before the agreement is signed. Missing any of them can mean fines or a weaker position in a later dispute.
Lead-Based Paint
For any property built before 1978, federal law requires the owner to disclose known information about lead-based paint hazards, provide copies of any existing reports, and give the lodger the EPA pamphlet “Protect Your Family From Lead in Your Home.” The lodger signs an acknowledgment.5US EPA. Lead-Based Paint Disclosure Rule (Section 1018 of Title X) Federal penalties for skipping this are substantial.
Bed Bugs
Civil Code Section 1954.603 requires a written notice before a new tenancy explaining how to report a suspected bed bug infestation. The notice has to be in at least 10-point type.6California Legislative Information. California Civil Code 1954.603 Section 1942.5 separately protects the lodger from retaliation for making a good-faith report.7California Legislative Information. California Civil Code 1942.5
Megan’s Law Notice
Every residential rental agreement entered into on or after April 1, 2006, must include a notice pointing the lodger to the California Department of Justice registered sex offender information at meganslaw.ca.gov. The required language is set by statute and must appear in at least 8-point type.8California Legislative Information. California Code, Civil Code CIV 2079.10a
Flood Hazard
Since July 1, 2018, California has required owners to disclose in the rental agreement whether the property sits in a special flood hazard area or an area of potential flooding, when the owner has actual knowledge. Actual knowledge includes written notice from a public agency, carrying flood insurance, or having a lender that requires flood coverage. The disclosure also directs the lodger to the Office of Emergency Services “My Hazards” tool and notes that the owner’s insurance does not cover the lodger’s personal belongings.
Fair Housing: You Can Choose, But Watch the Ad
The federal Fair Housing Act prohibits discrimination based on race, color, national origin, religion, sex, familial status, and disability.9U.S. Department of Housing and Urban Development. Housing Discrimination Under the Fair Housing Act An exemption, sometimes called the Mrs. Murphy exemption, covers owner-occupied dwellings with four or fewer units where the owner does not use a real estate agent.10Office of the Law Revision Counsel. 42 USC 3603 – Effective Dates of Certain Prohibitions Most room rentals qualify.
The exemption covers your choice of whom to rent to. It does not cover how you advertise. The advertising prohibition has no exemption, so a listing that says “no families with children” or expresses any protected-class preference violates federal law even for a single room in your own home. Keep ads focused on the room: size, rent, move-in date, house rules.
Signing, Copies, and Records
California recognizes handwritten and electronic signatures. Both parties should sign the same final version on the same date. Civil Code Section 1962 then requires the owner to provide a complete copy of the executed agreement to the lodger within 15 days, and the lodger can request another copy once per calendar year.11California Legislative Information. California Civil Code 1962
Keep records of every financial transaction: rent payments, the deposit, utility reimbursements. Digital receipts and bank transfer confirmations work. Hold onto them for several years after the arrangement ends, because either side could bring a civil claim within the applicable statute of limitations.
Call Your Insurer Before Move-In
Standard homeowners policies are written for owner-occupied residences, not rental operations. Rent out a room without telling your insurer and you risk a denied claim when something goes wrong, whether it is a slip on the stairs, a kitchen fire, or water damage to the lodger’s belongings. Contact your carrier first. Some will continue coverage unchanged, some will add a “unit rented to others” endorsement for an additional premium, and some will steer you toward a different policy. The lodger should carry renter’s insurance for their own property and personal liability.
A Note on Taxes
Rent you collect from a room in your home is taxable federal income reported on Schedule E (Form 1040), with a proportional share of expenses — mortgage interest, property taxes, utilities, insurance, maintenance, and depreciation — deductible based on the portion of the home being rented.12Internal Revenue Service. Topic No. 415, Renting Residential and Vacation Property Rental expense deductions cannot exceed gross rental income from the room, so you cannot generate a paper loss to offset wages. IRS Publication 527 lays out the reporting rules.13Internal Revenue Service. About Publication 527, Residential Rental Property Keep clean records on both sides from day one.