How to File a Property Tax Appeal in California

Why California Property Tax Appeals Exist

Under Proposition 13, your property's assessed value is generally set when you buy it and can only increase by up to 2% per year. But market values move faster than that cap — in both directions. When home prices drop or your property is worth less than its Prop 13 base value, you may be entitled to a temporary reduction under Proposition 8 (decline-in-value). And in any year, if the assessor has simply made an error — wrong square footage, incorrect property class, missed exemption — you can challenge that too.

The appeals process is administered by your county's Assessment Appeals Board (AAB), an independent body that reviews the assessor's valuation. The AAB is not part of the assessor's office — it exists specifically to give homeowners a fair hearing.

Grounds for an Appeal

Per BOE Publication 30, you can appeal your assessment on any of the following grounds:

• Decline in value (Prop 8): Your property's market value on January 1 is lower than its current assessed value.
• Incorrect base year value: The assessor used the wrong purchase price or calculated the base year incorrectly after a change of ownership.
• Misclassification: Your property is taxed as a different type than it actually is (e.g., commercial rate applied to residential property).
• Erroneous assessment: The assessor used incorrect data — wrong size, wrong number of units, improvements that don't exist, or physical damage not reflected in value.
• Missed exemption: You qualified for a homeowner's exemption, disabled veteran's exemption, or other reduction that was not applied.

The 8-Step Appeal Process

Here is exactly how the process works from start to finish. Steps marked Done for you are handled entirely by PropTaxSaver. Steps marked Guided are ones PropTaxSaver walks you through. The remaining two steps are yours alone.

1. 01

   Check whether your assessed value is too high

   ✦ Done for you

   Your property tax bill is based on the assessed value assigned by your county assessor. Look at your most recent assessment notice or annual tax bill. If your property's market value is lower than that assessed value, you have grounds to appeal. You can also appeal if you believe the assessor made an error in classifying the property, missed an exemption, or used an incorrect base year value.

   PropTaxSaver pulls your current assessed value and benchmarks it against recent market data automatically.

2. 02

   Know your filing deadline

   ✦ Done for you

   Missing the deadline means waiting another full year. California law sets two main windows. For the annual roll, you generally have from July 2 through September 15 to file. Some counties extend this to November 30. If you received a formal Assessment Notice (Prop 8 or supplemental), you have 60 days from the mailing date on that notice. Escape assessments also carry a 60-day deadline from the notice date.

   PropTaxSaver tracks your county's exact filing window and sends reminders so the deadline never sneaks up on you.

3. 03

   File with the Assessment Appeals Board — not the Assessor

   ✦ Done for you

   This is the most common mistake homeowners make. You do not send your appeal to the county assessor — you file with the Clerk of the Assessment Appeals Board (AAB) in your county. In some smaller counties this function is handled by a Hearing Officer. You can find the correct office and contact information on your county's website or through the California State Board of Equalization (BOE).

   PropTaxSaver identifies the correct AAB office for your county and provides the exact filing address and instructions.

4. 04

   Complete and submit the appeal application

   ✦ Done for you

   Use form BOE-305-AH, "Assessment Appeal Application," which is available from the BOE or your county's AAB office. The form asks for your parcel number (APN), the current assessed value, your opinion of the correct value, and the grounds for your appeal. Be specific — vague claims like "the value seems high" are weaker than citing comparable sales or a recent appraisal. Most counties also charge a small filing fee.

   PropTaxSaver pre-fills your BOE-305-AH with your APN, assessed value, and grounds for appeal — ready to sign and submit.

5. 05

   Gather your evidence

   ✦ Done for you

   The burden of proof is on you, the appellant. The assessor's value is presumed correct until you present evidence to the contrary. The most persuasive evidence is recent comparable sales — homes similar to yours that sold for less than your assessed value around January 1 of the tax year. You can also use a licensed appraisal, income data for rental properties, or repair cost estimates for physical damage. Organize everything clearly before your hearing date.

   PropTaxSaver builds your full evidence packet — comparable sales, property data analysis, value benchmarking, and a formatted case summary — not just comps. Everything the Board needs to rule in your favor, organized and ready to submit.

6. 06

   Exchange information with the Assessor before the hearing

   ◎ Guided

   Before your hearing, you have the right to contact the county assessor's office to review the data they used to arrive at your assessed value. This step is valuable — it lets you spot errors (wrong square footage, incorrect number of bathrooms, improvements that were never built) and sometimes leads to an informal settlement before you ever appear before the Board.

   PropTaxSaver shows you what to ask for and what to look for when reviewing the assessor's data, so you go in knowing exactly what to challenge.

7. 07

   Attend your hearing and present your case

   You handle this

   Hearings before the Assessment Appeals Board are relatively informal but follow a structured process. You and the assessor's representative each present evidence, and board members may ask questions. Speak to the value, not your personal financial situation — the Board can only consider property value, not whether you can afford to pay. Bring printed copies of all your evidence for the Board and the assessor.

8. 08

   Receive the Board's decision and get your refund

   You handle this

   After the hearing the Board issues a written decision. If your appeal is successful, the assessor adjusts your assessed value and the county will issue a refund for any taxes overpaid — with interest at the rate set by state law. If you disagree with the decision you can file an application for reconsideration within 60 days, or pursue further review in Superior Court.

What Actually Happens at the Hearing

Most Assessment Appeals Board hearings are informal and last under 30 minutes for residential cases. You and a representative from the assessor's office each present your evidence. Board members — typically three — may ask questions. The hearing is not a courtroom: no formal rules of evidence apply, but you should treat it professionally.

After the Hearing: Refunds, Reconsideration, and Further Review

Once the Board issues its decision, the assessor is required to update the roll to reflect the new value. If you overpaid taxes based on the higher value, the county tax collector will issue a refund — with interest. The interest rate is set by state law and compounds from the date of your original overpayment.

If your appeal is denied or you believe the Board made an error, you have options:

• Application for reconsideration: File within 60 days of the decision date if there was a procedural error or new evidence that was not available at the time.
• Writ of mandate / Superior Court: A higher level of review for significant disputes, typically requiring legal counsel.