An Assessment Appeal Application is the official form used to protest your property's assessed value in California. It's filed with your county's Assessment Appeals Board (also called the Board of Equalization in some counties).
Unlike Texas, which has a simple Notice of Protest, California requires a more formal application. You must specify the grounds for your appeal, the value you believe is correct, and sign under penalty of perjury.
The filing window is limited: July 2 through November 30 for regular assessments (or within 60 days of a supplemental assessment notice).
California's Prop 13 usually keeps your assessed value below market value. But there's one exception: when markets decline after you purchase.
If you bought during a peak and values dropped, your Prop 13 base (purchase price + 2% per year) might actually exceed current market value. That's when a California appeal makes sense.
The Assessment Appeal Application is your tool to request a "decline in value" reduction. If granted, your assessment drops to current market value—and your taxes drop with it.
Maria bought a home in San Diego County for $850,000 in 2022. By 2024, the market had declined and similar homes were selling for $780,000.
She filed an Assessment Appeal Application stating:
• Current assessed value: $867,000 (original purchase + 2% increases)
• Requested value: $780,000 (based on current market)
• Grounds: Decline in value (assessed value exceeds market value)
The Appeals Board agreed and reduced her assessment to $785,000—saving her approximately $820 annually until the market recovers.
For regular annual assessments, file between July 2 and November 30. For supplemental assessments (triggered by purchase or new construction), you have 60 days from the notice date.
You'll receive a hearing date, typically within 1-2 years depending on county backlog. At the hearing, you present evidence that your market value is below your assessed value. The board makes a binding decision.
Not required, but helpful for larger reductions. You can support your case with comparable sales data, real estate agent opinions, or a professional appraisal. Stronger evidence improves your chances.