In California, someone can live with you without being on the lease, but whether that’s allowed depends on what your rental agreement says and whether your landlord has agreed to it in writing. State law doesn’t automatically forbid an extra occupant, and it doesn’t set a specific number of days that turns a guest into a tenant. Your lease does. And when the lease is violated, the consequences land on you, the leaseholder, not on the person who moved in.
Start With What Your Lease Allows
Three clauses in a standard California residential lease decide this question. A guest policy defines how long a visitor can stay before being treated as an occupant. An occupancy limit caps the number of people allowed to live in the unit. A subletting clause controls whether you can let someone else pay part of the rent or take over space. Nearly every California lease prohibits subletting without the landlord’s written consent.
If any of these clauses is exceeded, you are in breach of contract the moment it happens, even if nobody notices for months. A quiet landlord is not a waiver. The violation gives the landlord grounds to act whenever they choose to enforce it.
When a Guest Becomes an Unauthorized Occupant
You may have heard numbers like 14 days in six months or 7 consecutive nights. Those come from common lease language, not from California statute. If your lease uses those thresholds, those thresholds govern you. If your lease is silent on duration, the question turns on behavior: is this person visiting, or living here?
Courts and landlords look at practical signs. Paying part of the rent. Receiving mail at the address. Keeping clothes, furniture, and daily belongings in the unit. Having no other residence. Once presence looks permanent rather than temporary, the landlord can treat the person as an unauthorized occupant regardless of what you call the arrangement.
What the Landlord Can Do to You
The first step is usually a written three-day notice to perform covenant or quit. Under California’s Code of Civil Procedure, this notice identifies the lease violation and gives you three days, not counting weekends and court holidays, to fix it. In practice, that means having the unauthorized person move out.1California Legislative Information. California Code of Civil Procedure CCP 1161
If you don’t comply, the landlord can file an unlawful detainer lawsuit. Unauthorized occupancy and subletting are specifically listed as at-fault just cause for eviction under California’s Tenant Protection Act, so long tenure in the unit does not shield you from this particular ground.2California Legislative Information. California Civil Code 1946.2
The damage outlasts the eviction itself. An eviction filing can appear on tenant screening reports for up to seven years, which makes renting the next place significantly harder. Any unpaid rent or damages the court awards can land in collections and hit your credit report.
What Protects the Person Not on the Lease
The landlord cannot force the occupant out through self-help. Changing the locks, shutting off utilities, or removing belongings is illegal under California Civil Code Section 789.3, and a landlord who does any of it faces penalties of at least $250 per violation plus actual damages and attorney’s fees.3California Legislative Information. California Civil Code 789.3
If the occupant has been paying you rent, they may have established rights as a subtenant. In that case California effectively treats you as their landlord, and the property owner who wants everyone out typically files an unlawful detainer naming both of you so the court can address each person’s right to possession.4California Courts. Eviction Cases in California The three-day notice must also be served on any subtenant actually living in the unit. Skipping that step can delay or defeat the eviction.1California Legislative Information. California Code of Civil Procedure CCP 1161
How to Add Someone to the Lease the Right Way
Ask before they move in. Submit a written request identifying the proposed occupant and the arrangement. Expect the landlord to require an application and standard screening: credit check, background check, income verification.
California caps the screening fee. Civil Code Section 1950.6 sets a base fee of $30, adjusted annually for the Consumer Price Index, and the landlord has to give you an itemized receipt showing how the fee was spent.5California Legislative Information. California Civil Code CIV 1950.6 If the applicant passes, everyone signs an addendum or a new lease that officially adds them.
Watch the deposit. If the addition triggers a new security deposit, California caps it at one month’s rent for most landlords. Small landlords who are individuals and own no more than two rental properties with four or fewer total units can charge up to two months’ rent.6California Legislative Information. California Civil Code 1950.5
If the Landlord Says No
If your lease requires landlord consent for subletting but says (or is read to say) that consent cannot be unreasonably withheld, Civil Code Section 1995.310 lets you pursue contract damages or even terminate the lease when the landlord unreasonably blocks a transfer.7California Legislative Information. California Civil Code 1995.310 Many leases, however, give the landlord absolute discretion. Read the clause before assuming you have leverage.
What Adding Someone Means for You
You stay fully on the hook. You and the new co-tenant are both responsible for every lease obligation, including the full rent. If your new roommate stops paying their share, the landlord comes after you for all of it. Trust the person before you tie your tenancy to theirs.
Occupancy Limits Cannot Target Families
Landlords can set reasonable occupancy limits, but those limits cannot be used to keep families with children out. Familial status is a protected class under federal and California fair housing law.8Equal Housing. Familial Status Fact Sheet
California’s Civil Rights Department uses a two-persons-per-bedroom-plus-one guideline as a screening tool when evaluating whether a restriction may be discriminatory. It is not a hard legal rule; the full analysis also looks at bedroom size, unit layout, and local building codes.9California Civil Rights Department. Background History of Residential Occupancy Standards A landlord who caps a two-bedroom unit at two people total is almost certainly violating fair housing law. Infants are generally not counted as additional occupants, and landlords cannot require children of different genders to have separate bedrooms.8Equal Housing. Familial Status Fact Sheet
Live-In Caregivers Are Treated Differently
If you or someone in your household has a disability and needs a live-in aide, fair housing law requires the landlord to allow that person in the unit as a reasonable accommodation. California’s Civil Rights Department lists allowing a live-in aide as an example.10California Civil Rights Department. Reasonable Accommodations for People with Disabilities The landlord can deny the request only if it would create an undue financial burden, fundamentally change their operations, or pose a direct safety threat. An ordinary occupancy limit, by itself, is not a valid reason to refuse.
Put the request in writing, tie it to the disability-related need, and keep a copy. You don’t have to disclose the diagnosis, just the functional need.
Insurance Coverage Does Not Follow Them Automatically
A standard renter’s policy covers your belongings and your liability for visitors who get hurt in your home. It generally will not cover the personal property of a roommate or occupant who isn’t a named insured. If their laptop is stolen or their clothes burn in a fire, your policy won’t pay.
Either add the person to your policy as a named insured, if your insurer allows it, or have them buy their own renter’s insurance. It’s cheap to fix now and expensive to fix later.
Money You Collect May Be Taxable
If your roommate pays you more than their share of actual household costs, the IRS treats the excess as rental income. Splitting utilities down the middle is cost-sharing. Charging $800 a month for a bedroom when your share of costs is lower creates reportable income, which goes on Schedule E of your federal return even when the roommate is a friend or family member.11Internal Revenue Service. Publication 527 – Residential Rental Property Track the arrangement. Unreported rental income found in an audit means back taxes, interest, and possible penalties.