How to Appeal Your LA County Property Tax Assessment Before the November 30 Deadline

Can I appeal my Los Angeles County property tax assessment?

Yes. LA County homeowners can challenge an over-assessed property value through two paths: a free informal Prop 8 Decline-in-Value review (Form RP-87, no filing fee, no hearing) and a formal appeal with the Assessment Appeals Board (Form AAB-100, $46 filing fee). Both share the same November 30, 2026 deadline. Filing cannot increase your taxes. A successful appeal averages $1,100–$1,845 in annual savings for LA County homeowners.

By Jason Franklin | September 14, 2026

Most Woodland Hills and West Hills homeowners know their property taxes are based on their purchase price — that’s Prop 13. What far fewer know is that California law lets you temporarily reduce that assessed value if your home’s current market value has dropped below it. That mechanism is Prop 8. And the window to use it closes every year on November 30.

If you’ve never checked whether your assessed value is still accurate, now is the time. You have about ten weeks.

What Prop 13 and Prop 8 Actually Mean for Your Tax Bill

When you bought your home, your property tax assessment was set at your purchase price. Under Prop 13, that base is locked in and can only increase by a maximum of 2% per year — regardless of what the market does. That’s the protection that makes owning in California financially viable long-term. (If you’re thinking about selling and want to understand how that Prop 13 base transfers to your next home, here’s how Prop 19 portability works.)

What most people miss is the flip side. Prop 13 protects you from rapid increases when prices rise, but it doesn’t automatically adjust downward when prices fall. That adjustment is optional — and it requires you to ask for it.

California Revenue & Taxation Code §51 allows a temporary reduction in your assessed value when your home’s market value on January 1 of the current tax year falls below your current Prop 13 factored base. The county adjusts your tax for that year. When the market recovers, the county can restore your Prop 13 base — and they will, without sending you a notice.

This is a one-year-at-a-time relief. It doesn’t carry forward automatically. And the filing deadline is firm.

Who Should Take a Look at Their Assessment

Not every homeowner will qualify. In a market that’s been appreciating — which describes most of the SFV over the long run — your market value typically exceeds your Prop 13 base, and an appeal wouldn’t yield a reduction. But several situations are worth checking:

• You bought in 2021–2022. Prices surged during the low-rate years, and many buyers paid above levels that have since normalized in parts of the market. If comparable homes around January 1, 2026, were selling below what you paid, you may have a case.
• You bought new construction. Newly constructed homes are sometimes assessed on developer pricing that includes soft costs and market premiums. Comparable resale sales nearby might support a lower figure.
• You’re in West Hills or parts of Tarzana. West Hills home prices were down 0.5% year-over-year through mid-2026. For buyers who purchased at the previous peak, the math might favor an appeal.
• You’ve never checked. Many homeowners assume their assessment is correct and never look. Spending fifteen minutes confirming could save you over $1,000 per year.

Long-time owners — people who bought before 2018 in most SFV neighborhoods — likely won’t qualify, because their Prop 13 base is well below current market value. But if you’ve purchased more recently, it’s worth the check.

How to Find Out If You’re Over-Assessed

Start at assessor.lacounty.gov. Search by your property address or Assessor Identification Number (AIN). Note your current enrolled value — this is your Prop 13 assessed value for the 2025–26 tax year.

Then pull comparable sales on Zillow or Redfin: homes similar to yours in the same neighborhood — comparable size, condition, lot, and configuration — that closed near January 1, 2026. If those comps come in below your enrolled value, you likely have grounds for an appeal.

The math is direct. If your enrolled value is $1.35 million and comparable homes were trading around $1.2 million near January 1, 2026, you’re potentially over-assessed by $150,000. At Woodland Hills’ effective rate of approximately 1.1–1.4% — which is what you’ll find when you factor in LA County bonds and special assessments on top of the Prop 13 base rate — that’s $1,650–$2,100 in excess taxes per year. (For a full breakdown of how that effective rate is calculated, this guide covers the components in detail.)

It’s worth spending thirty minutes to find out.

The Two Filing Tracks — and Why You Should Use Both

LA County offers two ways to challenge your assessment. Los Angeles County officially recommends filing both on the same day.

Track 1: The Free Informal Review (Form RP-87)

File Form RP-87 directly with the Los Angeles County Office of the Assessor. There’s no cost, no hearing, and no risk — the Assessor reviews your comparable sales evidence and either reduces your assessed value or holds it. Your taxes cannot increase through this process under any circumstances.

For a straightforward decline-in-value case with three to five clean comparable sales, the informal review often resolves things without any further steps.

Track 2: The Formal Appeal (Form AAB-100, $46 fee)

The Assessment Appeals Board process is more structured. There’s a $46 per-parcel filing fee, and your case may be scheduled for a hearing where you present evidence to a hearing officer. The fee is non-refundable, but you can withdraw the appeal at no additional cost if the informal review resolves your case first.

Here’s why the formal appeal matters: if the Assessor’s office doesn’t resolve your informal review before November 30, that informal application alone doesn’t preserve your rights past the deadline. Filing the AAB-100 at the same time keeps your case open. It’s $46 worth of insurance.

Building Your Case

Your evidence is comparable sales. The goal is to show the Assessor and Appeals Board — with hard data — that your home’s market value on January 1, 2026, was lower than your current enrolled value.

Identify three to five comparable sales that meet these criteria:

1. Same neighborhood or competing market area as your property
2. Closed near January 1, 2026 — within 90 days is ideal (October 2025 through March 2026)
3. Similar in size, condition, lot size, and configuration — the more comparable, the stronger your case

Pull these from Zillow or Redfin and save each listing page with the address, close date, sale price, and key property details. The Assessor and the Appeals Board both want to see specific closed sales data — not market averages, not estimates, not Zestimates.

One thing to be clear on: you’re presenting the market value as of January 1, 2026 specifically — not today’s value and not your original purchase price. The valuation date matters, and your comps should cluster around it.

If you’re not sure how to structure this, a local agent can pull a simple comp set for your address using the same MLS data the Assessor uses. It’s not complicated — homeowners with a solid three-comp package win reductions on their own all the time.

When to Use Professional Help

If pulling comparable sales and filing forms sounds like more than you want to handle, services like Ownwell manage the research and filing for you on a contingency basis. You pay nothing unless they win a reduction, and their fee in California is 35% of the first year’s savings. On a $1,200-per-year reduction, you’d net roughly $780 annually after the fee — still meaningful, and it compounds every year you maintain the lower assessment.

For clear-cut cases with straightforward comps, many homeowners do this successfully on their own. For more complex situations — new construction with unusual assessments, properties with significant improvements, or cases where the comparable sales picture is complicated — professional help removes the guesswork and handles the process entirely.

Either way: don’t let the deadline pass without at least checking.

One Important Thing to Know About Prop 8 Reductions

A Prop 8 reduction is temporary. The County Assessor reviews your property’s market value each January 1. Once your market value climbs back above your Prop 13 factored base, the county can restore your assessed value to the full Prop 13 amount — and they don’t have to notify you first.

This means that in a recovering or appreciating market, your reduced assessment may quietly revert. If you receive a Prop 8 reduction this year and want to maintain it in future years, you’ll need to re-file each year before November 30. If the market has recovered and your assessed value is restored, an appeal that year simply won’t yield a reduction — you’re back to Prop 13 protection as intended.

Over the long run, Prop 13 remains the more powerful protection for most SFV homeowners. But in the short term, when market conditions support a reduction, Prop 8 is worth using.

Frequently Asked Questions

Can filing a property tax appeal increase my taxes in LA County?

No. The LA County property tax appeal process cannot result in a higher assessment. Your taxes will either be reduced or remain the same — they cannot be increased through the informal review or the formal appeal. This is explicitly protected under California law, and the county makes this clear in its own filing materials.

How do I find my current assessed value in Los Angeles County?

Visit assessor.lacounty.gov and search by your property address or Assessor Identification Number (AIN). Your enrolled value — the figure used to calculate your annual tax bill — is listed there. That’s the number you’ll compare against recent comparable sales to determine whether you’re over-assessed.

What’s the difference between the Prop 8 informal review and the formal appeal?

The informal Prop 8 review (Form RP-87) is free, has no hearing, and is resolved directly by the Assessor’s office. The formal appeal (Form AAB-100) costs $46 per parcel and may involve a hearing before the Assessment Appeals Board. LA County recommends filing both simultaneously, because the informal review alone doesn’t preserve your case if the Assessor doesn’t respond before November 30. If the informal review resolves things first, you withdraw the formal appeal at no additional cost.

What evidence do I need to win a property tax appeal in LA County?

The strongest evidence is three to five comparable closed sales near January 1, 2026 — homes in your neighborhood with similar size, condition, and lot — that sold below your current assessed value. Pull these from Zillow or Redfin and document each with the address, close date, sale price, and key property details. The Assessor and the Appeals Board prefer hard data over general market statements or automated valuations.

Does a Prop 8 reduction carry forward to future years automatically?

No. A Prop 8 reduction is granted on a year-by-year basis. The county reassesses your property each January 1, and once your market value rises above your Prop 13 factored base, the county restores your original assessed value — often without advance notice. If you want to maintain the reduced assessment in future years, you need to re-file each year before November 30. When the market has recovered and your assessed value is restored, an appeal simply won’t produce a reduction.

The November 30 deadline is about ten weeks away. If you’ve never checked your assessment, fifteen minutes on the LA County Assessor’s website could tell you whether you’re leaving money on the table.

If you’re thinking through this alongside a broader decision — whether to stay, sell, or reposition your property in the West Valley — I’m happy to pull the comparable sales data for your specific address and give you a read on whether an appeal makes sense. Reach out anytime at jasonfranklinre.com.

About Jason Franklin
Jason Franklin is a licensed real estate broker and REALTOR® with The Dinsky Team at Equity Union in Sherman Oaks, California. A San Fernando Valley native licensed since 2016, he has closed over $50 million in career sales and ranks among the top 4% of local producers, specializing in luxury listings, investment properties, value-add flips, and seller representation across the West San Fernando Valley and Conejo Valley. Connect with Jason at jasonfranklinre.com.