A California property tax protest is filed as a formal assessment appeal on state form BOE-305-AH with the Clerk of the Board in the county where your property sits, and the window to file runs from July 2 through either September 15 or November 30 depending on the county. A successful appeal lowers your assessed value and triggers a refund of what you overpaid, with interest. Before filing anything, though, pick up the phone and call the assessor.
Call the Assessor Before You File
The California Board of Equalization recommends contacting your county assessor before starting a formal appeal.1California State Board of Equalization. Assessment Appeals Frequently Asked Questions Most offices run an informal review where you submit basic evidence showing why the value looks too high, and the staff may agree to adjust it without a hearing or any paperwork beyond their own internal form. This costs nothing, moves faster than a formal appeal, and resolves a surprising number of disputes. If you can’t agree on a value, your right to file a formal appeal is still there.
When You Have Grounds to Protest
California’s Revenue and Taxation Code requires every property to be taxed at the lower of two figures: its factored base year value (the original assessed value adjusted upward by no more than 2 percent per year under Proposition 13) or its current fair market value.2California Legislative Information. California Code RTC 51 – Base Year Values When the number on your bill exceeds either benchmark, you have grounds to protest.
Decline in Value (Proposition 8)
A decline-in-value appeal applies when your property’s current market value has dropped below its factored base year value as of the January 1 lien date. This commonly happens during downturns, after natural disasters, or when neighborhood conditions change for the worse. Assessors are supposed to catch these drops and reduce assessments automatically, but they don’t always get it right.3California State Board of Equalization. Decline in Value – Proposition 8 A Proposition 8 reduction is temporary: the assessor reviews it annually and will restore the value toward the factored base year value as the market recovers.
Base Year Value
When you buy a property or complete new construction, the assessor sets a new base year value reflecting fair market value at the time of that event. If that number looks too high — higher than what you paid, or higher than market conditions supported when construction finished — you can challenge it. The window is limited. You must file during the regular equalization period for the year the new value first appears on the roll, or during any of the three following years. After that, the base year value becomes conclusive.4California Legislative Information. California Revenue and Taxation Code Section 80
Filing Deadlines You Can’t Miss
The Regular Window
The regular filing period opens July 2. In counties where the assessor mails assessment notices to all property owners on the secured roll by August 1, the deadline is September 15. In counties that don’t meet that August 1 mailing requirement, the deadline extends to November 30.5California Legislative Information. California Code RTC 1603 – Assessment Appeal Filing Period Los Angeles County uses the extended November 30 deadline.6County of Los Angeles Assessment Appeals Board. Assessment Appeals Board Miss the deadline for your county and you lose the right to challenge that year’s assessment, so check with your Clerk of the Board early in the summer. The Board of Equalization publishes an annual letter identifying each county’s deadline.
Supplemental and Escape Assessments
Appealing a supplemental assessment (triggered by a change in ownership or new construction mid-year) or an escape assessment (a correction to a prior roll) runs on a different clock: 60 days from the date on the notice, regardless of month.7California State Board of Equalization. Letter to County Assessors and County Clerks of the Boards – County Assessment Appeals Filing Period for 2025 These notices can arrive at any time of year. Don’t assume the July–November window covers them.
Filing the Application
The official form is BOE-305-AH, the Assessment Appeal Application. Older references call it the “Application for Changed Assessment,” but the name changed in 2015.8California Department of Tax and Fee Administration. Assessment Appeals You get the current form from the Clerk of the Board in the county where the property sits, and most counties post it online.
The form asks for your Assessor’s Parcel Number (on your tax bill), the current assessed value you’re contesting, your opinion of the correct value, and the reason for the appeal. Pick your opinion of value carefully. It needs to reflect actual fair market value as of the lien date, supported by evidence you’ll bring to the hearing,9California State Board of Equalization. BOE-305-AH – Assessment Appeal Application and if the board fails to act within two years, that number automatically becomes your assessed value.
Some counties charge a non-refundable filing fee. Amounts vary: San Joaquin County charges $30, Los Angeles County charges $46, and not every county charges one at all.10Los Angeles County Board of Supervisors. Assessment Appeals Information Confirm the fee with your clerk so it doesn’t hold up your application.
Keep Paying Your Taxes
Filing a protest does not pause your obligation to pay. You must keep paying the full amount on time while the appeal moves through the system. Skip a payment waiting for a decision and the county will add late penalties, which the Assessment Appeals Board has no power to remove.11OC Clerk of the Board. Assessment Appeals FAQs If the board later reduces your assessed value, the county refunds the overpayment plus interest. Treat it as paying under protest: the money isn’t lost, just temporarily out of pocket.
Evidence That Wins Appeals
Filing the form is the easy part. Winning depends on what you bring to the hearing. For a residential property, the most persuasive evidence is recent comparable sales — properties similar in size, age, condition, and location that sold close to the January 1 lien date. Three to five strong comparables, with clear adjustments for differences like an extra bathroom or a larger lot, give the board something concrete to work with.
A professional appraisal from a licensed appraiser carries significant weight, especially for unusual properties where good comparables are hard to find. Expect to pay roughly $250 to $1,000 for a single-family home depending on complexity and location. The appraisal has to value the property as of the January 1 lien date for the tax year in question, not the date you hired the appraiser. If the appraisal uses a different date, the board may discount or disregard it.
Other useful evidence includes photos documenting deferred maintenance or damage, repair estimates from licensed contractors, and listing-to-sale price data showing broader market softness in your neighborhood. Organize everything clearly. Boards hear dozens of cases and appreciate a tight presentation.
The Hearing
After you file, the Clerk of the Board schedules a hearing before either a three-member Assessment Appeals Board or a single hearing officer. The board or officer is independent from the assessor’s office. A hearing officer tends to run things less formally than a full panel, but the legal standard is the same.12OC Clerk of the Board. How To Prepare For Your Hearing
You present your evidence first, then the assessor’s representative presents theirs. Both sides can question each other’s data, and board members often ask their own questions about property condition, comparable sales adjustments, or market trends. A lawyer isn’t required. Many homeowners handle their own appeals.
Who Has to Prove What
A common misconception trips people up here. For owner-occupied single-family homes that qualify for the homeowner’s exemption, the law favors the taxpayer. Revenue and Taxation Code Section 167 creates a rebuttable presumption in the taxpayer’s favor, meaning the assessor bears the initial burden of justifying the assessed value, as long as you’ve supplied all legally required information to the assessor.13California Legislative Information. California Code RTC 167 – Burden of Proof in Certain Tax Matters The presumption disappears if the appeal involves an escape assessment caused by your failure to file a change-in-ownership statement or obtain a construction permit. For every other property type — commercial, investment, and non-owner-occupied residential — the taxpayer carries the burden of proving the assessment is wrong.
Settling Before the Hearing
Not every protest reaches a hearing. After reviewing your application and evidence, the assessor’s office may offer a stipulated value, essentially a negotiated settlement. Both sides sign a stipulation form (BOE-305-S) and submit it to the board for approval.14California State Board of Equalization. Stipulation Agreement – BOE-305-S If the board accepts, the appeal is resolved without a hearing. This happens often and is worth pursuing. The board can reject a stipulation, in which case the matter gets set for hearing.
The Two-Year Rule
California law gives the appeals board two years from the end of the filing period to hear your case and issue a decision. If the board fails to act within that window, your opinion of value, the number you wrote on the application, automatically becomes the assessed value for the tax year in question. This is a powerful protection against bureaucratic backlog, which is exactly why the number on the form matters so much. Two exceptions can prevent this outcome: a written mutual agreement to extend the deadline, or your failure to provide complete information as required by law. The board can also consolidate your application with another one of yours that has an extension, but only with your written consent.15California State Board of Equalization. Letter to County Assessors – Extension of the Two-Year Deadline for County Boards
After the Decision
Win, and the county adjusts the tax roll and issues a refund of the overpaid amount plus interest. Refund processing typically takes six to eight weeks after the decision.12OC Clerk of the Board. How To Prepare For Your Hearing The reduction applies only to the specific tax year or years in the application. For decline-in-value appeals, you may need to refile the following year if market conditions haven’t recovered, since the assessor reassesses annually.
Lose, and you can file again next year if grounds still exist. You also have the option of challenging the board’s decision in Superior Court, though litigation costs rarely make sense for typical residential assessments. If a court challenge is a possibility, request written findings of fact from the board at or before the hearing. You’ll need them.
What a Refund Does to Your Federal Taxes
A property tax refund can carry federal income tax consequences. Under the IRS tax benefit rule, if you deducted property taxes on a prior year’s federal return and that deduction reduced your tax liability, you must report the refund as income in the year you receive it. If you received the refund in the same year you paid the taxes, you simply reduce your deduction by the refund amount instead. Taxpayers who didn’t itemize in the year the original tax was paid don’t need to report any part of the refund as income.16Internal Revenue Service. Publication 525 – Taxable and Nontaxable Income With the federal cap on state and local tax deductions still at $10,000 for most filers, many California homeowners are already at the limit, which can reduce or eliminate the taxable portion of a refund. IRS Publication 525 has a worksheet for the exact calculation.
Hiring Someone to Handle It
You can run a protest yourself, and many homeowners do. For higher-value properties or complex commercial appeals, a property tax attorney or consultant may be worth the cost. Many work on contingency, taking a percentage of the tax savings rather than charging upfront. Rates vary. Roughly 25 to 40 percent of the first year’s savings is common, though some firms charge more or less depending on property type and complexity.
If you hire a representative, confirm they’ll handle both preparation and the hearing itself. Ask whether filing fees and appraisal costs are included in the contingency or billed separately. Be wary of anyone who guarantees a specific outcome before analyzing your property. No one can promise how an appeals board will rule.