Alameda, CA: Property Tax Appeal Instructions (2025-26)

Key facts at a glance

The 60-second primer

Your property tax value is the lesser of (a) your Prop 13 factored base-year value (purchase/new-construction value plus up to 2% inflation per year), or (b) market value on January 1 (the "lien date"). If market value is lower, you may get a temporary Prop 8 reduction for that year. Prop 8 reductions are reviewed every year and can rise more than 2% as the market recovers, though never above your Prop 13 track.

Every California county handles appeals differently. If you own property in multiple counties, take a look at our county-specific guides for all California counties.

New to property tax appeals? Start with the fundamentals in our Appeal 101 article, which covers the core concepts that apply across California.

The Alameda "Informal" Route (Prop 8 Review)

Alameda lets you request a Prop 8 review directly with the Assessor before filing a formal appeal. Most homeowners should start with the informal route because it's free, faster, and often resolves the issue without a hearing. Your goal is to show the Assessor your January 1 market value is below your enrolled value.

Step 1: Check your enrolled value

Look up your parcel on the county site to confirm the current assessed value you're trying to beat. Understanding the difference between land value and improvement value can reveal where assessment errors hide.

Step 2: Build credible comps around January 1

Here is the complete guide on how to find and build comparible analysis matching on bed/bath count, living area, lot, condition, and location. Create a simple adjustment table and aim for a supported opinion of value (not just “lower than assessed”).

For Alameda’s e-form, include at least one sale as close to January 1 as possible and no later than March 31. This requirement aligns with California’s general “≤ 90 days after the valuation date” rule used in formal appeals.

Step 3: Submit the informal request (by December 31)

File online via the county's Decline in Market Value e-form (or PDF) by December 31, 2025 for the 2025–26 assessment year. A county appraiser reviews your data and any sales they have; if January 1 market value is lower, they'll reduce the assessment for the fiscal year beginning July 1.

Step 4: Watch the calendar

The Assessor completes the roll in June and mails value notices in the latter part of July. If you disagree with the Assessor's findings or haven't received a response by the formal appeal deadline, proceed to file a formal appeal.

The Alameda “Formal” Route (Assessment Appeal)

If the informal review doesn’t resolve it, use the Assessment Appeals Board (AAB) process.

Step 1: Check timing and what you’re appealing

Confirm you’re inside the filing window shown in Key facts. Alameda posts the annual dates and application instructions on the Clerk’s site here (see the year’s filing notice here). For a Supplemental or Escape assessment, you have 60 days from the notice date; for a Calamity reassessment, you have 6 months from the notice date.

Step 2: File the application

File online via the county's assessment appeal portal here, or mail the current BOE‑305‑AH application form to the Clerk of the Board. Submit one application per APN and per roll year. If you're appealing the current regular roll value, select "Decline in Value (Prop 8)" as the basis. Pay the non-refundable $50 fee per application source. Properties owned by trusts or LLCs have special signing requirements—check our guide on filing as a trustee or LLC to avoid dismissals.

Step 3: Choose who hears your case

Eligible residential cases may be assigned to a Hearing Officer; otherwise you’ll be scheduled before the three‑member AAB. If you prefer the AAB, don’t elect the Hearing Officer option.

Step 4: Build and submit your evidence

Use the “DIY Evidence Checklist” below to assemble your packet focused on the January 1 lien date. Comparable sales must be no later than 90 days after the valuation date (for a decline‑in‑value appeal, that’s January 1 of the year you’re appealing) see BOE Pub 30. Upload documents ahead of the hearing using the county portal Upload Hearing Documents and serve the Assessor if requested. To see the Assessor’s packet in advance, make a written “Exchange of Information” request under R&T § 1606 link at least 10 days before the hearing.

Step 5: Hearing day and outcome

Arrive early and check in; you’ll be sworn in. You present first, then the Assessor; Board members may ask questions. Decisions are often mailed after the hearing. If you reach agreement with the Assessor beforehand, you can sign a stipulation instead of appearing. Outcomes can go up or down based on the evidence.

DIY Evidence Checklist (that actually works)

Assessors reward specific types of evidence and ignore others. For the complete breakdown of what appeals boards actually care about, see our dedicated guide. Many homeowners waste time on documentation that boards ignore—avoid those pitfalls by reading about the most persistent appeal myths.

You'll need 3–5 comparables within ~0.5–1 mile, similar size/age/condition, closed near January 1 (and within the allowable window). Highlight adjustments. Include condition proof such as photos, contractor estimates, permits, and anything that demonstrates deferred maintenance or functional issues as of January 1. Add a brief summary explaining neighborhood trends and why your subject trails the comps (or why your comps require downward adjustments).

Frequently Asked Questions

Can my assessment jump more than 2% in one year?

Yes, when the market rebounds. Prop 8 reductions are temporary. As market value rises, your assessment can increase by more than 2% annually until it hits your Prop 13 factored base year ceiling. No limit up or down. For more on upside risks and whether appealing can backfire, see our dedicated guide.

Do I need to reapply for a Prop 8 reduction every year?

Nope. Alameda automatically reviews your value each July. You'll get a Notification of Assessed Value card showing their decision. Only file again if you disagree.

What if I disagree with the Assessor's Prop 8 decision?

File a formal appeal with the Assessment Appeals Board by September 15. See the "Formal Route" section above for details.

Why aren't Prop 8 reductions permanent?

California law (Rev. & Tax. Code § 51) requires annual comparison of your Prop 13 factored value vs. market value. You get the lower number. When the market recovers, so does your assessment (up to your Prop 13 track).

How does my assessment change when values rise? (Example)

If 2020 market value had been $855,000 instead, your assessment would be $855,000 and you'd stay on Prop 8 review another year.

Where can I verify my parcel information?

County Property Search has everything you need.

Rules are local. Always verify the current instructions with Alameda County and county's official sites before filing.

Key Alameda-Specific Reminders

The Assessor says they proactively review for declines. Still, owners can and should submit an informal request if they see a gap. If you miss the regular window, you can't appeal that year's regular roll value. Prop 8 reductions are one-year at a time and get re-tested annually.

Other Bay Area counties like Contra Costa and San Francisco have different informal windows and procedures worth comparing if you own multiple properties.

For common misconceptions about California appeals, see our myths busted guide.

How AppealArc helps

We do the heavy lifting. We pull same-neighborhood, same-vintage sales and build a clean, lien-date-focused grid that assessors actually like to read.