How do I appeal in Santa Clara County?

File an Assessment Appeal Application with the Clerk of the Board of Supervisors by September 15 (regular roll) or November 30 (supplemental).

What if my home value has recovered?

Under Prop 13, the county can restore your assessed value up to the factored base year value if market conditions improve.

Guides/California/Santa Clara County

Santa Clara County, California

How to Appeal Property Taxes in Santa Clara County (2026)

Appeal Deadline

September 15 (for regular roll; supplemental/escape: 60 days from notice)

County Assessor Appeal Forms

Overview

Santa Clara County, the heart of Silicon Valley, has approximately 500,000 parcels and some of the highest property values in the nation. The county assessor manages assessments under Prop 13 rules, but the tech industry's volatility means market values can fluctuate significantly. Homeowners in cities like San Jose, Palo Alto, Cupertino, and Mountain View should regularly check whether their assessed value exceeds current market value.

Step-by-Step Appeal Process

Review your assessment at sccassessor.org

Compare your assessed value to current comparable sales

If market value is below assessed value, file an appeal with the Clerk of the Board

Regular roll deadline: September 15. Supplemental: November 30

Prepare evidence showing current market value

Attend the hearing or submit evidence in writing

What Evidence Do You Need?

Comparable sales from your neighborhood

Market data for your specific city/area

Appraisal from a licensed appraiser

Evidence of property or neighborhood issues

Common Reasons for Successful Appeals

Silicon Valley market fluctuations create gaps between assessed and market value

Layoffs at major tech companies have affected local demand

Rising interest rates have reduced buying power for high-value homes

Supplemental assessments from recent purchases may be too high

Tips for Success

1Focus on sales in your specific city — Palo Alto and San Jose markets can differ greatly

2Tech layoffs since 2022 have impacted demand in certain neighborhoods

3The county assessor offers an informal review process — try this first

Frequently Asked Questions

Check Your Assessment in Santa Clara County

Enter your address to see if you're overpaying and get a professional appeal packet for $49.

Free Assessment Check

This guide is for informational purposes only and does not constitute legal advice. Deadlines and procedures may change. Always verify current information with your county assessor.