How to Appeal Your Property Taxes in California (2026 Guide)

Most guides tell you California's property tax appeal deadline is September 15. For 47 of the state's 58 counties that is wrong by two and a half months, and for the other 11 it is exactly right. Getting the wrong one costs you the entire year.

This guide gives you your county's real 2026 date, and then does something no other California guide does first: it shows you how to work out in about two minutes whether you have a case at all. Under Proposition 13, most California homeowners do not, and no amount of evidence changes that.

The two-minute version. Your assessed value is the LESSER of your Prop 13 base year value or current market value. If the number on your roll is already below what your home would sell for, you have no appeal. If it is above, you do, and the California DIY Appeal Kit walks you through the whole filing for $29 flat. See the California kit

When is the California property tax appeal deadline in 2026?

The regular filing period opens July 2 everywhere in the state under Revenue & Taxation Code §1603(b). It closes on one of two dates:

The split is not arbitrary. §1603(b)(3) extends the last day to November 30 in any county where the assessor does not mail a §619 notice of assessed value by August 1. Most California assessors do not, so most of the state runs to November 30.

Do not try to infer your date from whether a notice showed up in your mailbox. Read the Board of Equalization's current-year County Assessment Appeals Filing Period letter, or call your Clerk of the Board. Our national appeal deadline calendar carries California's dates with the BOE letter cited as the source, alongside every other state.

Two separate clocks exist alongside the regular one. Supplemental and escape assessments run 60 days from the mailing date printed on the notice, except in counties that have resolved under §1605(c) to run those 60 days from the tax bill instead. Los Angeles has done exactly that, and it works in your favor. A calamity reassessment runs six months.

The board cannot extend a filing period for any reason. There is no good-cause exception in California.

Do I even have a California property tax appeal?

This is the question to settle before anything else, and it is the reason most California appeals should never be filed. The answer turns entirely on Proposition 13.

Under R&T §51(a), your taxable value is the lesser of two numbers:

1. Your base year value (set when you bought the home or completed new construction), compounded each year by the California CPI inflation factor, capped at 2% per year; or
2. Full cash value, meaning market value, as of the January 1 lien date.

So take the total assessed value off your roll or tax bill and set it next to an honest estimate of what your home would have sold for on January 1, 2026.

• Assessed value is lower than market value. You have no case. This is the normal situation for anyone who has owned through a price run-up, and it is why a household that bought in 2011 can be assessed at half of what the house is worth. An appeal cannot lower a value that is already below market.
• Assessed value is higher than market value. The gap is your case, and Proposition 8 (codified at §51) is the mechanism that corrects it.

A Prop 8 reduction is temporary and applies to one year only. The assessor re-reviews it annually, and you must file again for every year you disagree, even while a prior year is still pending.

If you bought recently, near the top, or your neighborhood has fallen since your purchase, run this test carefully. That is where California appeals actually live.

What form do I file, and who do I file it with?

You file form BOE-305-AH, the Assessment Appeal Application, with your county Clerk of the Board. Not the Assessor. This trips people up constantly, because the Assessor is who set the value and is the obvious place to send a complaint. The appeals board is a separate agency, and a form sent to the wrong office is not a filing.

The BOE hosts a copy of the form at boe.ca.gov, but it is watermarked SAMPLE ONLY. Every appeal must be filed on the official form for your county. Get it from your Clerk of the Board, or use the county's online filing system.

Filling it out, the parts that matter:

• One parcel, one roll year, one assessment type per application. A supplemental or escape assessment needs its own separate application on its own 60-day clock.
• Column A is the roll value. Column B is your opinion of value. Leaving Column B blank makes the application incomplete.
• Answer YES to the owner-occupied single-family principal residence question if it applies. That single checkbox is worth more than anything else on the form. See below.
• Box 8 is the claim for refund. Check it. It preserves your route to Superior Court.
• Box 7 is findings of fact, which must be requested and paid for before your hearing ends. Without findings you cannot meaningfully go to court.
• Sign under penalty of perjury with an original signature, and file with any county fee by 5:00 p.m. on the deadline. Postmark counts.

Does the assessor have to prove their value, or do I?

On your own home, the assessor goes first. This is the most valuable rule in California property tax law and most homeowners have never heard of it.

Under R&T §167 and 18 CCR Rule 321(d), any hearing involving an owner-occupied single-family dwelling that is your principal residence and qualifies for the homeowners' exemption under §218 carries a rebuttable presumption in favor of you, the taxpayer, provided you supplied the assessor all information required by law. The assessor must present first and rebut that presumption.

Rule 321(f) goes further: the presumption that the assessor did his job properly is not evidence and shall not be considered in the board's deliberations. And Rule 321(e) provides that on a change in ownership, your purchase price is rebuttably presumed to be full cash value, so whoever wants to depart from it carries the burden, which is usually the assessor.

Claim the §167 presumption on the form. It is a checkbox that shifts who has to prove what.

The evidence rules are where California appeals are won and lost. Comps that closed more than 90 days after January 1 are inadmissible, evidence you handed the assessor is invisible to the board, and the board can raise your value. The California DIY Appeal Kit lays out every one of these rules with the statute behind it, plus a ready-to-edit application letter, for $29. Get the California kit

What evidence wins a California assessment appeal?

Three or more comparable sales of similar homes nearby is the working standard California clerks publish. But the timing rule is the one that decides cases:

Sales must have closed no more than 90 days AFTER January 1 of the appeal year. The board may not consider anything later. BOE Publication 30 calls this the most common error in all assessment appeals. Sales well before the lien date are perfectly fine; it is the summer sales people reach for that are fatal.

Beyond the comps:

• Arm's-length sales only. No family transfers, no forced or quick sales, no off-market deals between people who know each other.
• Your own assessor's property record, checked for errors in square footage, lot size, year built, and bed and bath count. A plain factual error can often be fixed by a free phone call with no appeal at all.
• A price-per-square-foot worksheet. Publication 30 supplies one. Living area excludes garages, porches, and patios.
• Photographs of your property's defects and of each comparable. Publication 30 recommends driving by every comp you rely on.
• Your current roll value. Filing opens July 2 but bills do not mail until October, so you often have to call the assessor to get the number you are appealing.

What happens after I file?

The clerk schedules your hearing and must give you at least 45 days' notice; some counties give 60.

Your backstop is the two-year rule in §1604: the board must hear and decide within two years of a timely filing, and if it does not, the opinion of value YOU stated becomes the taxable value by operation of law. The exceptions are narrow, covering a written extension you agreed to, consolidated applications, your failure to supply required information, or pending related litigation.

At the hearing, present everything again. Only evidence actually put in front of the board counts. Documents you gave the assessor months ago are invisible to it. You must attend or be represented by someone thoroughly familiar with the facts, and failing to appear can mean denial.

An appeals board decision is final and cannot be reheard. To go further you must already have a claim for refund on file (Box 8), and then you have six months from its denial under §5141 to sue in Superior Court. You will also need those written findings of fact, plus the transcript.

What are the biggest mistakes California homeowners make?

Assuming September 15. It applies in only 11 counties. Assuming November 30 in Alameda, San Francisco, Santa Clara, or Ventura costs you the whole year, and Santa Clara pairs that early close with a $290 non-refundable residential filing fee.

Treating an informal review as an appeal. Most assessors offer a free decline-in-value review and Publication 30 tells you to talk to your assessor first. Do it. But it is discretionary, not statutory, and it does not extend or toll your appeal deadline. Its own window is often completely different, with Orange County running January 1 to April 30. Filing an informal request while the formal window closes is the single most common way California homeowners lose a year.

Forgetting the board can raise your assessment. §1610.8 lets it determine full value without limitation by your opinion of value. Publication 30 says plainly that a board can increase, decrease, or leave an assessment unchanged.

Not paying the tax bill. An appeal does not stay collection. You must pay in full and on time while it is pending, and the board has no power to remove late-payment penalties or interest.

Choosing a hearing officer without thinking about it. Many counties route residential appeals to a single hearing officer, which is less formal and usually faster. But in some counties, Orange among them, written findings of fact are available only from a full appeals board, and you need findings to go to Superior Court.

Filing fees by county

There is no statewide filing fee, and most California counties charge nothing. The exceptions are worth knowing before you file:

• Los Angeles: $46 per application, non-refundable, hardship waiver available.
• Santa Clara: $290 per residential parcel or application, non-refundable. Waivers for applicants receiving public assistance.
• San Diego and Orange: no published assessment appeal filing fee.

Findings of fact carry a separate charge in essentially every county, including counties with no filing fee. County fee schedules change without notice, so confirm with your Clerk of the Board at the time you file. Counties that charge a fee must offer a hardship waiver.

Where to go from here

Settle the Prop 13 question first. If your assessed value is below market, stop, and check again next year. If it is above, your county's date is either September 15 or November 30, and you should confirm which from the BOE letter rather than from a blog, including this one.

For the full process, the state-by-state comparison, and the statutes behind each rule:

• California property tax appeals for the state overview
• Every state's 2026 appeal deadline, sourced and dated
• The California DIY Appeal Kit, $29, with the deadline rules, the evidence standards, form BOE-305-AH, and a ready-to-edit application letter

We do not hold per-parcel records for California, so we cannot run your comps for you, and we would rather say that than sell you a lookup that returns nothing. The kit is $29 instead of $49 for exactly that reason: you pull your own comps, and it shows you precisely how.

Appeal Your California Assessment Yourself

We do not hold per-parcel records for California, so there is no free lookup here, and we say so rather than sending you to a search that cannot find you. What we do have is the California DIY Appeal Kit: the deadline rules, the official form, the evidence the boards actually accept, and a ready-to-edit appeal letter, for $29 flat. You pull your own comps and keep 100% of your savings.