How to Appeal Property Taxes in California

California's property tax system is fundamentally different from every other state due to Proposition 13 (1978). Under Prop 13, your property's assessed value is set at its purchase price and can only increase by a maximum of 2% per year — regardless of how much the market goes up.

This means most California homeowners who've owned for years have assessments far BELOW market value (which is great). Appeals are primarily relevant in these situations:

1. You bought recently and the purchase-based assessment is higher than current market value (market dropped since you bought)

1. The county applied an incorrect base year value

1. You received a "supplemental assessment" after purchase that seems too high

1. The market has declined below your current assessed value (Prop 8 temporary reduction)

To appeal, file an Application for Changed Assessment with your County Assessment Appeals Board between September 15 and November 30 (some counties extend to December 31). There's no filing fee.

The hearing is before a 3-member panel. Present comparable sales showing your property's market value is below its current assessed value. If successful, your assessment is reduced temporarily (it reverts back when the market recovers — this is the "Prop 8" reduction).

Common mistakes California homeowners make:

1. Appealing when Prop 13 is protecting them — If you've owned for 10+ years, your assessment is probably BELOW market. Don't appeal — you'd be inviting the assessor to look more closely.

1. Not understanding the difference between Prop 13 base and Prop 8 reduction — A Prop 8 reduction is temporary. When the market recovers, your value goes back up (to the Prop 13 base + 2%/year).

1. Missing the September 15 - November 30 window — California's window is specific and some counties require filing by September 15 for the current year.

1. Not filing after a purchase in a declining market — If you bought in 2022 and values dropped 10-15% in 2023-2024, file immediately.

1. Confusing assessed value with market value — Thanks to Prop 13, these are often very different in California.

Pro tips for California appeals:

• Prop 13 means appeals are mainly for recent buyers or declining markets. If you've owned for 5+ years, you're likely already paying below-market assessment.

• Los Angeles County alone processes ~200,000 assessment appeals. The system handles volume.

• A Prop 8 reduction automatically "pops back" when values recover. Consider this when deciding if the effort is worth a temporary reduction.

• Prop 19 (2020) changed the rules for inherited properties. If you inherited a home, your assessment may have reset.

• The Homeowners' Exemption ($7,000 off assessed value) saves only ~$70/year but requires just a one-time filing. If you haven't filed, do it.