How to Appeal Your Property Tax Value in Los Angeles County

Overview

If you believe your property’s assessed value is too high, you can ask Los Angeles County to lower it.
There are two ways to do this:

Informal review with the Assessor’s Office using Form RP-87, and
Formal appeal with the Assessment Appeals Board using the BOE-305-AH form (or its online version).

Start with the RP-87 — it’s simple, free, and often works.
If you’re not satisfied with the result, you can still file a formal appeal before the annual deadline.

Simple Explanation

When home prices drop, your property taxes should reflect that.
Los Angeles County gives you two steps to make it happen:

Ask the Assessor for a Decline-in-Value Review
Fill out Form RP-87 on the County Assessor’s website.
You’ll enter your property details, explain why you think the value is too high, and share a few comparable sales.
The Assessor will review your request and may reduce your value.
File a Formal Appeal if Needed
If the Assessor doesn’t reduce your value enough, you can appeal to an independent board called the Assessment Appeals Board.
You’ll use the county’s version of the BOE-305-AH form, filed online through lacaab.lacounty.gov.
The board listens to evidence from both you and the Assessor’s Office, then decides what your assessed value should be.

Detailed Explanation

1. Understanding the Law Behind It

California’s property tax system is based on two rules:

Proposition 13 (1978) caps how much your assessed value can increase each year.
Proposition 8 (1978) allows a temporary reduction when the market value on January 1 is lower than your assessed value.
This is called a “decline in value” review.

Under Revenue and Taxation Code § 51, the Assessor must use the lower of your factored base year value or your current market value each year.

2. The RP-87 “Decline-in-Value” Form

The RP-87 is Los Angeles County’s official form for requesting a Prop 8 reduction.
It’s available here.
It’s free, and you can submit it online or by mail. You’ll need:

Your parcel number (AIN)
Evidence that your market value fell — like recent comparable sales, a Zillow printout, or an appraisal
Contact info and signature

The Assessor reviews your request, compares your comps, and may lower your value.
You’ll be notified by mail if an adjustment is made.

Tip: This is not a formal appeal — it’s an informal review. You keep all your rights to appeal later.

3. Filing a Formal Appeal (BOE-305-AH)

If you disagree with the RP-87 result — or simply want to protect your rights — file a formal appeal with the Assessment Appeals Board.

Where to file: lacaab.lacounty.gov
Deadline:
- For most properties: July 2 – November 30 each year
- For supplemental or escape assessments: within 60 days of the notice date
What to file: Application for Changed Assessment (county version of BOE-305-AH)
What happens next:
You’ll receive a hearing date. At the hearing, you can present comps, appraisals, or other evidence showing your property’s value as of January 1.
The Board makes a binding decision, and the Assessor must follow it.

4. Summary Table

Step	Form	Who Reviews	Result	Deadline
Decline-in-Value Review	RP-87	County Assessor	Informal adjustment	July 2 – Nov 30 2025
Formal Appeal	BOE-305-AH (online via lacaab.lacounty.gov)	Assessment Appeals Board	Legally binding	July 2 – Nov 30 2025

5. Common Mistakes

Waiting for RP-87 results too long and missing the formal appeal deadline
Not providing comparable sales from around January 1 (the lien date)
Submitting emotional arguments (“value dropped after a remodel”) instead of market data

6. Best Practice

If you’re unsure whether the Assessor will act in time, file both:

RP-87 for a quick informal review, and
A formal appeal to preserve your rights before November 30.

You can withdraw the appeal later if the Assessor adjusts your value.

Links

✅ In short:
Try RP-87 first.
If you don’t get the reduction you think is fair, file a formal appeal before November 30.