California Property Tax Appeal Guide

What This Data Tells Us About Appeals in California

In California, property tax appeals are filed with the Assessment Appeals Board. The typical window is July 2 – September 15 for the regular roll; within 60 days for supplemental assessments, with the deadline most commonly falling in September. Filing fees reported for this state are $0–$30 (varies by county), and Lincoln Institute research plus state-reported data suggest roughly 52% of appeals result in some reduction when supported by comparable sales or documented errors.

California uses Proposition 13 base-year values. You can also request a Decline-in-Value review (Prop 8) if market value falls below assessed value, no filing fee. Appeals are driven by the gap between a parcel's assessed value and its actual market value — the calculator below turns that gap into an annualized dollar figure at your effective tax rate. The strongest evidence is three to five arms-length comparable sales from the past six to twelve months, plus documentation of any factual errors in the assessor's record (square footage, bedroom count, finished-basement status).

This guide is for informational purposes only and is not legal or tax advice. Deadlines, filing fees, success rates, and procedures vary by county within California and can change year to year. Always verify the current rules with your local assessor's office — or a licensed attorney or tax professional — before filing. Source: California Board of Equalization.