Rate Breakdown

Property taxes in San Mateo County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in San Mateo County

San Mateo County follows California’s Proposition 13 framework. Each parcel is assessed at its market value as of the 1975‑1976 base year, and the assessed value can increase by no more than 2 % per year, regardless of market fluctuations. The county assessor determines the assessed value, then applies the local “millage rate” – the amount of tax levied per $1,000 of assessed value. In 2024 the general county rate is approximately 1.12 mills, while cities, school districts, and special districts add their own rates. The combined rate in most San Mateo neighborhoods hovers between 1.1 % and 1.3 % of assessed value, which translates to roughly $1,100‑$1,300 in taxes for every $100,000 of assessed value.

Available Exemptions

California offers several exemptions that can reduce the taxable portion of your property. In San Mateo County you may be eligible for the following:

• Homeowner (Homestead) Exemption: Reduces the assessed value by $7,000 for owner‑occupied single‑family residences.
• Senior Citizen Property Tax Postponement: Allows homeowners age 62 or older with limited income to defer all or part of their property tax payments.
• Disabled Veteran Exemption: Provides a $5,000 reduction for qualified disabled veterans; additional reductions may apply for those with a 100 % service‑related disability.
• Veteran’s Exemption (Non‑Disabled): Grants a $5,000 reduction for veterans who served at least one year during a period of war, provided they meet income and residency requirements.

Eligibility is determined at the county assessor’s office. Applicants must submit the appropriate forms and supporting documentation before the filing deadline, typically November 30 of the tax year.

Payment Schedule & Deadlines

San Mateo County property taxes are due in two installments:

• First Installment: November 1 – December 10 (late payments incur a 10 % penalty).
• Second Installment: February 1 – April 10 (late payments incur a 10 % penalty and a $10 surcharge).

If you miss a deadline, the county adds the penalty to the outstanding balance and may place a tax lien on the property. To avoid penalties, you can set up automatic electronic funds transfers (EFT) or use the county’s online portal for recurring payments. Property owners may also qualify for a reduced rate under the “Parcel Tax Credit” if they meet low‑income criteria.

Appealing Your Assessment

If you believe your assessed value is inaccurate, you have the right to contest it. Follow these steps:

• File a Proposition 13 (Prop 13) Appeal: Submit the proper form (Form R‑7) to the San Mateo County Assessor’s Office by July 2 of the tax year.
• Gather Evidence: Compile recent comparable sales, appraisals, or evidence of property damage that support a lower value.
• Attend a Hearing: The Assessment Appeals Board will schedule a hearing, usually within 30‑45 days of filing. You may present your evidence in person or via written testimony.
• Decision & Further Review: If the Board denies your appeal, you can request a review by the Office of Tax Appeals (OTA) within 30 days of the decision.

Timely filing and thorough documentation are crucial. Many owners find it helpful to consult a property tax consultant or real‑estate attorney familiar with San Mateo County’s appraisal practices to improve their chances of a successful outcome.