Home › Guides › California appeal evidence
California homeowner guide · Reviewed September 6, 2026Evidence for a California assessment appeal. Make the valuation easy to follow.
A property-tax appeal is a valuation case. The strongest packet is usually not the longest one. It gives the assessor or assessment appeals board a clean answer to one question: what was this property worth on the relevant January 1 lien date?
Start with comparable sales
For a decline-in-value review, the BOE says the material typically includes comparable properties that sold close to January 1 and no later than March 31. Start with nearby sales of homes that are genuinely similar in location, size, age, use, and condition. Then explain meaningful differences instead of treating every sale price as interchangeable.
Include the documents that identify the property
- The assessment notice or tax bill, including the assessor's parcel number.
- A short property fact sheet with square footage, bed and bath count, lot size, and the assessment being challenged.
- Sales records or listing sheets for each comparable, with sale date, price, distance, and the source.
- Photos and repair records for real condition issues that affected market value on the valuation date.
- A recent purchase document if it is relevant to the date and circumstances of the appeal.
Keep condition claims concrete
"The house needs work" is hard to evaluate. Photos, contractor estimates, inspection findings, and dated repair records are more useful. Describe the issue, when it existed, and why it would affect a buyer's view of value. Do not pad a filing with cosmetic preferences or a current remodel that was not part of the property on January 1.
Use a simple comparison table
Put the subject property at the top, then list each comparable below it. A reader should be able to see the address, sale date, sale price, size, and major difference without hunting through attachments. If you make an adjustment, explain the basis. A transparent smaller case is better than a spreadsheet full of unexplained numbers.
Check the county instructions. Each county may set its own filing format, evidence exchange, and hearing procedures. Use the county guide hub before submitting anything.