San Mateo County · Renting & eviction
Renting in San Mateo County: the rules that apply
Unincorporated San Mateo County limits rent increases only for mobilehome park spaces and requires relocation pay when County code enforcement displaces tenants. It has no just-cause eviction rule of its own, so state law applies to covered units.
Key points
- Mobilehome rents: County rule, mobilehome park spaces only: increases are limited to 75% of the CPI change or 5%, whichever is less, once per 12 months.
- Rent cap: State law caps rent increases on covered units at 8.8% for increases taking effect August 1, 2026 through July 31, 2027.
- Just cause: State law: after 12 months of lawful occupancy, ending a tenancy in a covered unit needs a just cause; no county rule.
- Code displacement: County rule: households permanently displaced by County code enforcement get 3 times monthly HUD Fair Market Rent, plus up to $1,000 moving costs.
- Relocation pay: State law: no-fault evictions of covered units require 1 month's rent as relocation pay or a rent waiver, paid within 15 calendar days.
- Notice to end: State law: 60 days' notice to end a tenancy, or 30 days if the tenant has lived there less than 1 year.
Each rule below is marked San Mateo County code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.
San Mateo County's code applies in the unincorporated areas of the county. Cities in San Mateo County have their own codes and their own pages.
Rent increases
San Mateo County code County rule, mobilehome park spaces only: increases are limited to 75% of the CPI change or 5%, whichever is less, once per 12 months. State law caps rent increases on covered units at 8.8% for increases taking effect August 1, 2026 through July 31, 2027.
All 5 San Mateo County rules on rent increases, with the code text and the state law underneath →
Eviction and just cause
CA state law San Mateo County has no rule of its own on this, so California law applies. Just cause required: After 12 months of lawful occupancy, the owner may terminate only for a just cause stated in the notice (Civ. Code § 1946.2(a)). Just-cause eviction in California — the full state rule →
Relocation payments
San Mateo County code County rule: households permanently displaced by County code enforcement get 3 times monthly HUD Fair Market Rent, plus up to $1,000 moving costs. State law: no-fault evictions of covered units require 1 month's rent as relocation pay or a rent waiver, paid within 15 calendar days.
Notices
| Filing a copy with the city |
|
|---|---|
| What a notice must say |
|
| Notice of a rent increase | At least 30 days' notice for an increase of 10% or less; at least 90 days for an increase of more than 10% Applies: The 10% is measured against the rent charged at any time in the 12 months before the increase, counting all increases in that period together. |
|---|---|
| Notice to end a month-to-month tenancy (landlord) | 60 days' notice; 30 days if the tenant has lived there less than one year Applies: Where the unit is covered by just cause (Civ. Code § 1946.2) or a local ordinance, the notice must also state a qualifying cause. |
| Notice to end a month-to-month tenancy (tenant) | At least as long as the rental period (one month for a month-to-month tenancy) |
| 30-day notice when the unit is sold to an owner-occupant | 30 days' notice when a separately sellable unit is in escrow to a natural person who will live there for at least a year Applies: Notice within 120 days of opening escrow, given once, and all § 1946.1(d) conditions met. |
| Notice to pay rent or quit | 3 days, not counting Saturdays, Sundays and judicial holidays, stating the amount due and how to pay Applies: May be served any time within one year after the rent became due. |
| Notice to cure a lease violation or quit | 3 days, not counting Saturdays, Sundays and judicial holidays, to perform the broken lease term or leave |
| No fee for serving notices | A landlord may not charge the tenant a fee for serving or posting a notice |
Security deposits
CA state law San Mateo County has no rule of its own on this, so California law applies. Security deposit cap: One month's rent, on top of the first month's rent (Civ. Code § 1950.5(c)(1), (c)(6)). Deposit return deadline: 21 calendar days after the tenant moves out, with an itemized statement of any deductions (Civ. Code § 1950.5(h)(1)). California security deposit law — the full state rule →
Retaliation
| Protected activities |
|
|---|
CA state law Underneath, California law still applies. Retaliation protection period: For 180 days after a tenant complains about habitability (to the landlord or an agency), the landlord may not evict, raise rent or cut services in retaliation (Civ. Code § 1942.5(a), (b)). Retaliatory eviction in California — the full state rule →
Harassment and lockouts
CA state law San Mateo County has no rule of its own on this, so California law applies. Lockouts and self-help eviction banned: A landlord may not change locks, remove doors or windows, or remove the tenant's belongings to force a tenant out (Civ. Code § 789.3(b)). Utility shutoffs banned: A landlord may not cut off water, heat, electricity, gas or other utilities to force a tenant out (Civ. Code § 789.3(a)). Tenant harassment and lockouts in California — the full state rule →
Repairs and habitability
CA state law San Mateo County has no rule of its own on this, so California law applies. Duty to keep the unit habitable: The landlord must deliver a unit fit to live in and repair conditions that make it untenantable (Civ. Code § 1941). Repair and deduct: A tenant may make a repair the landlord neglects and deduct the cost from rent, up to one month's rent, no more than twice in any 12 months (Civ. Code § 1942(a)). Habitability and repair-and-deduct — the full state rule →
Landlord entry
CA state law San Mateo County has no rule of its own on this, so California law applies. Landlord entry notice: Reasonable written notice, presumed to be 24 hours, and entry only during normal business hours (Civ. Code § 1954(d)(1), (e)). Landlord entry notice in California — the full state rule →
Hotel and short-term rental tax
| Tax rate |
|
|---|---|
| Who collects it |
|
Other San Mateo County rules on this
San Mateo County's code also has these chapters. We have not summarized their values on this page yet; read them in the library.
- Mobilehome Rent Control (Ch. 1.30) — mobilehome park spaces only
Who this affects
Frequently asked questions
Does a landlord in San Mateo County need a reason to evict?
State law: after 12 months of lawful occupancy, ending a tenancy in a covered unit needs a just cause; no county rule.
How much notice does a San Mateo County landlord have to give?
State law: 60 days' notice to end a tenancy, or 30 days if the tenant has lived there less than 1 year.
How much can a San Mateo County landlord charge for a security deposit?
San Mateo County has no local rule on this that we found (checked October 2026); state law applies: One month's rent, on top of the first month's rent (Civ. Code § 1950.5(c)(1), (c)(6)).
What is the hotel tax on short-term rentals in San Mateo County?
San Mateo County's code: 10% of the rent. (In effect since October 2, 1990.) (§ 5.136.020); Each operator collects the tax from every guest at the same time as the rent. (§ 5.136.040).
General information, not legal advice.
Ask about a specific San Mateo County property
Ask GoCodebook how these rules apply to your address and get an answer that cites the section.
Ask your question