Which deadline is yours?
California's window opens July 2 and closes September 15 or November 30, depending on whether the county assessor mails assessment notices to all secured-roll taxpayers by August 1.2
Most California counties, including Los Angeles, Orange, San Diego, Riverside, San Bernardino and Sacramento.1
In these 11 counties, the 2026 regular window closed on September 15:1
- Alameda
- Alpine
- Inyo
- Kings
- Mono
- Placer
- San Francisco
- San Luis Obispo
- Santa Clara
- Sierra
- Ventura
Check your county's assessment appeals board for its date.
See your free savings estimateTwo rules to know: Prop 13 and Prop 8
Proposition 13. Under Proposition 13, annual increases in your base-year value are generally limited to 2 percent, except when a property changes ownership or has new construction.3
Proposition 8. Under Proposition 8 (Revenue and Taxation Code section 51), the assessor must each year enroll the lesser of your factored base-year value or your market value on January 1.4
- Asking for a review
- Most county assessors will review a possible decline in value on your request, sometimes informally, but how and when to ask varies by county.4
- How long it applies
- A decline-in-value reduction applies to that year. The assessor reviews it annually, and the value can rise back toward your factored base-year value.2
How to file in California
Talk to the assessor first. Assessor's staff can explain your assessed value and review information you provide. If they find an error, they may be able to correct it, and you may not need to file an appeal.6
Get your county's form. Appeals go on the official Assessment Appeal Application for your county, from the clerk of the appeals board; many counties post it online. In its guide, the State Board of Equalization (BOE) shows a sample: form BOE-305-AH.6
Enter two values. The form asks for the value on the roll and your opinion of market value. Without your opinion of value, it is deemed incomplete and returned.6
File on time, and keep paying. Some counties charge a filing fee (for example $46 in Los Angeles County, with a hardship waiver); others may not.5 You still must pay your property tax on time while an appeal is pending.2
What the appeals board weighs
California's local appeals boards are independent agencies, separate from the assessor's office.6 An appeals board can lower, raise or confirm a value based on the evidence.2 It can't lower one simply because you pay more taxes than your neighbor, or reduce your taxes because you can't afford to pay.6
“The only evidence that an appeals board can consider is the evidence that you and the Assessor present at your assessment appeal hearing.”
According to the BOE, in most residential appeals the most reliable evidence of market value is the sale of similar properties, known as comparable sales.7
What happens at the hearing
In California, once you file, the clerk sets a hearing and must give you at least 45 days' notice. Hearings are less formal than court, and you don't need an attorney or an agent, but you must attend or be represented by someone thoroughly familiar with the facts of your appeal.8
Burden of proof. For an owner-occupied single-family home that is your principal residence and qualifies for the homeowners' exemption, California law creates a rebuttable presumption in your favor if you gave the assessor all the information the law requires, and the assessor presents evidence first.8
