If California has over-valued your home, you overpay property tax every year until you fix it. Filing an appeal is a standard, homeowner-friendly process — here is exactly how it works in California, including the deadline, the governing law, and the five steps to file.
The California deadline
The appeal window in California is typically July - November, and the filing deadline is September 15 to November 30 (county-dependent). Miss it and you generally wait a full year, so check your assessment notice the moment it arrives. See the national deadline calendar for how this compares.
How California values your home
California assesses property at 100% of market value, so the value on your notice is what the county believes your home would sell for. Compare it directly to recent sales. Under Proposition 13, California caps assessed value at the acquisition base year plus up to 2% annual growth, though value can be lowered when market value drops below that base. The process is authorized under Cal. Rev. & Tax. Code § 1603 (Proposition 13).
How to appeal your property taxes in California
Step 1. Compare your assessed value on the annual notice to your Proposition 13 base-year value.
Step 2. Request an informal review with the county assessor (Prop 8 decline-in-value) first.
Step 3. File an Application for Changed Assessment with the county Assessment Appeals Board (Sept 15 - Nov 30).
Step 4. Prepare comparable sales as of the January 1 lien date to prove market value.
Step 5. Present evidence at the Assessment Appeals Board hearing.
Build your evidence
The strongest case is a tight set of comparable sales — 3 to 5 similar homes near you that sold for less than your assessed value — plus any property-record errors you can document. You can also make an unequal-assessment argument if comparable homes are assessed for less than yours.
Don't forget exemptions
An appeal lowers your value, but a homestead exemption cuts your taxable base directly — and the two stack. Confirm you're enrolled with your county before you file.
The shortcut
Checking comps and building the packet is where most homeowners give up. TaxAppealAgent does it for you: check your California property for $4.99 (credited), and if you're over-assessed we assemble the comparable-sales evidence and a California-specific appeal letter for a flat $29. You file it and keep 100% of the savings. See the full California appeal guide.