San Mateo County, California

Requires all real property to be assessed by the County Assessor. The roll is processed by the Controller and serves as the basis for all property tax billing.

Governed by California Revenue and Taxation Code; assessed values are enrolled annually by July 1.

applies when — Applies to parcels within specific service areas (e.g., sewer maintenance, mosquito abatement, flood control districts).

Fixed or variable charges added to the property tax bill for specific services. These are not based on ad valorem rates but on service-specific formulas defined by the district.

Levied annually as part of the secured property tax bill.

applies when — Applies to parcels located within the boundaries of a school district or special district that has passed a voter-approved bond measure.

Additional ad valorem tax rates added to the base 1% rate to fund debt service on local bonds. The specific rate varies by district and is calculated based on the assessed value of the parcel.

Authorized under California law for local government debt service; reported annually in the County Tax Rate Book.

≈ $13,990/yr on a $1,399,000 median

A base tax rate of 1.00% of the assessed value of the property. The assessed value is 100% of the full cash value. Exemptions include the Homeowners Property Tax Exemption, which provides a $7,000 reduction in the assessed value of a primary residence.

Established by California Constitution Article XIIIA (Proposition 13); applied annually to the secured roll.

≈ $13,990/yr on a $1,399,000 median

applies when — Applies to residential parcels located within a designated Mello-Roos Community Facilities District (CFD) established by a local agency and approved by a two-thirds vote.

Levies an annual direct, non-ad valorem special tax directly on the parcel's secured property tax bill to fund designated community infrastructure (e.g., roads, sewer facilities, school facilities, emergency services) and repay municipal debt bonds. Unlike standard Proposition 13 taxes, Mello-Roos levies are not restricted to property valuation or the 1% cap; they are determined via an adopted Rate and Method of Apportionment (RMA) based on square footage, dwelling units, or lot acreage. Levies constitute a primary lien on the real property, subject to rapid judicial foreclosure upon tax default under accelerated statutory procedures.

Cal. Gov. Code §§ 53311–53368.3.

≈ $13,990/yr on a $1,399,000 median

applies when — Applies to parcels situated within designated Very High Fire Hazard Severity Zones (VHFHSZ) or State Responsibility Areas (SRA).

Imposes an ongoing legal obligation on the parcel owner to maintain a continuous 100-foot defensible space buffer around all occupied structures: Zone 1 (0 to 30 feet) requiring intensive fuel removal, clearing dead vegetation, and limbing trees 6 feet from the ground; Zone 2 (30 to 100 feet) requiring reduced fuel/brush thinning. Failure to comply exposes the parcel to local/CAL FIRE abatement liens and misdemeanor citations. Under Cal. Civ. Code § 1102.19, sellers must provide buyers with written documentation of compliance with local defensible space laws.

Cal. Pub. Res. Code § 4291; Cal. Gov. Code § 51182; Cal. Civ. Code § 1102.19.

applies when — Applies to parcels situated within a State Geologist designated Alquist-Priolo Earthquake Fault Zone (typically within 500 feet of a known active fault trace).

Prohibits the construction of any structure for human occupancy across the trace of an active fault. Enforces a mandatory parcel-specific geologic investigation by a licensed engineering geologist prior to the issuance of any building permit, requiring a mandatory setback (typically a minimum of 50 feet) from any mapped active surface fault trace. Universal disclosure to prospective purchasers on the statutory Natural Hazard Disclosure form is required upon transfer.

Cal. Pub. Res. Code §§ 2621–2630.

applies when — Applies to parcels in single-family residential zones that are not located on wetlands, hazardous waste sites, very high fire hazard zones (unless mitigated), earthquake fault zones (unless compliant with state seismic standards), or prime farmland/historic districts.

Requires local municipalities to ministerially approve, without discretionary review or CEQA scrutiny: (1) a two-unit residential development on a single-family lot (duplex), and/or (2) an urban lot split creating two parcels of roughly equal size (minimum 40% of the original lot area, each at least 1,200 sq. ft.). If a lot split is executed, the applicant must sign an affidavit certifying intention to occupy one of the housing units as their principal residence for a minimum of three years. Preempts local requirements for more than 4-foot side/rear setbacks and local parking minimums if located within 0.5 miles of transit.

Cal. Gov. Code §§ 65852.21 and 66411.7 (effective Jan 1, 2022 via SB 9).

Mandates local governments to ministerially approve attached/detached Accessory Dwelling Units (ADUs) and Junior ADUs (JADUs) on any single-family or multi-family zoned parcel without discretionary hearings or CEQA review within 60 days. Preempts local setbacks (mandating maximum 4-foot side and rear setbacks), prohibits minimum lot size restrictions for ADUs, bans owner-occupancy requirements (for ADUs permitted prior to 2025/pursuant to recent code updates), prohibits local utility impact fees on units under 750 sq. ft., and renders void and unenforceable any private HOA deed restriction or CC&R that prohibits or unreasonably restricts ADU construction.

Cal. Gov. Code §§ 65852.2 and 65852.22 (amended continuously through recent legislative sessions).

applies when — Applies to parcels situated within a common interest development (condominium project, planned development, community apartment project, or stock cooperative) with recorded CC&Rs and a common interest owners' association.

Binds the parcel to enforceable covenants, conditions, and restrictions (CC&Rs) running with the land. Empowers the association to levy regular and special assessments that become enforceable liens upon the parcel; restricts regular assessment increases exceeding 20% or special assessments exceeding 5% without member vote; establishes strict statutory limits on judicial or non-judicial foreclosure for delinquent assessments (requires delinquent regular assessments of at least $1,800 or delinquency of at least 12 months, subject to a mandatory 90-day post-sale right of redemption under Cal. Civ. Code § 5715); and overrides local HOA rules restricting accessory dwelling units, solar installations, or reasonable drought-tolerant landscaping.

Cal. Civ. Code §§ 4000–6150 (comprehensively recodified effective Jan 1, 2014).

applies when — Applies to first-lien mortgages or deeds of trust secured by an owner-occupied, 1-to-4 unit residential property.

Imposes pre-foreclosure servicing requirements on mortgage servicers before an NOD can be recorded: requires a mandatory 30-day pre-default contact or due diligence period (Cal. Civ. Code § 2923.55) to explore loss-mitigation options; strictly prohibits 'dual tracking' (recording an NOD or NOTS or conducting a sale while a complete loss-mitigation application is pending); guarantees a single point of contact (SPOC); and empowers borrowers to obtain injunctive relief, actual damages, and statutory penalties up to $50,000 for material willful violations.

Cal. Civ. Code §§ 2923.55, 2923.6, 2924.12 (originally enacted 2012; permanent provisions reenacted Jan 1, 2019).

Permits lenders to execute a non-judicial trustee's sale upon borrower default without prior court approval. The statute establishes strict timeline stages: recording of a Notice of Default (NOD) initiating a mandatory 90-day statutory cure/reinstatement period (under Cal. Civ. Code § 2924c, borrower can reinstate up to 5 business days before sale); followed by recording, posting, and publishing a Notice of Trustee Sale (NOTS) giving at least 20 days notice before the auction date. A trustee's non-judicial sale is definitive with no post-sale statutory right of redemption for the borrower, and the foreclosing lender is barred by anti-deficiency rules (Cal. Code Civ. Proc. § 580d) from seeking a deficiency judgment.

Cal. Civ. Code §§ 2924–2924k; Cal. Code Civ. Proc. § 580d.

Obligates sellers or their agents to deliver a statutory Natural Hazard Disclosure Statement certifying whether the parcel lies in any of six designated state/federal hazard zones: (1) FEMA Special Flood Hazard Area (100-year flood), (2) Area of Potential Flooding from Dam Inundation, (3) Very High Fire Hazard Severity Zone (VHFHSZ), (4) Wildland Fire Area (State Responsibility Area), (5) Earthquake Fault Zone (Alquist-Priolo), or (6) Seismic Hazard Zone (liquefaction/landslide). For parcels mapped inside these zones, state-mandated land-use setbacks, development restrictions, defensible space maintenance, mandatory flood insurance, or seismic retrofit obligations attach.

Cal. Civ. Code §§ 1103–1103.14.

Mandates that prospective sellers and listing/selling agents deliver a fully executed statutory Real Estate Transfer Disclosure Statement (TDS) disclosing all known material parcel defects, structural issues, boundary encroachments, unpermitted modifications, environmental hazards, and zoning variances. Failure to deliver allows the prospective buyer a statutory right of rescission (3 days after personal delivery or 5 days after mailing) and grounds for civil damages.

Cal. Civ. Code §§ 1102–1102.19.

applies when — The residential dwelling must be owned and occupied by the taxpayer as their principal place of residence on the January 1 lien date.

Reduces the taxable assessed value of the qualifying owner-occupied principal residence by $7,000 against the county assessment roll, generating a direct tax savings of approximately $70 annually (computed as $7,000 × 1% base rate). Formula: Net Taxable Assessed Value = Gross Factored Base Year Value - $7,000 exemption.

Cal. Const. art. XIII, § 3(k); Cal. Rev. & Tax. Code § 218.

Establishes a base ad valorem tax rate capped at 1.0% of assessed value plus voter-approved local indebtedness and direct assessments (typically resulting in an effective tax rate of 1.1% to 1.25%). The assessed base year value is established at acquisition/change in ownership or completion of new construction, with annual valuation inflation adjustments capped at the lesser of 2.0% or the California Consumer Price Index (CCPI). Formula: Total Annual Property Tax = [(Base Year Assessed Value × (1 + Inflation Factor capped at 2%)^n) - Eligible Exemptions] × (1.0% Base Rate + Voter-Approved Bond Rates) + Fixed Special Assessments / Parcel Taxes.

Cal. Const. art. XIII A (enacted June 6, 1978 via Proposition 13; codified in Cal. Rev. & Tax. Code §§ 50 et seq.).

≈ $13,990/yr on a $1,399,000 median