2026 Appeal Deadline Guides / California
Alameda County, CA Property Tax Appeal Deadline 2026
The regular filing window for a 2026 assessment appeal to the Alameda County Assessment Appeals Board runs July 2 through September 15, 2026. For supplemental or escape assessments, you instead have 60 days from the notice date.
⏳ 16 days left until the Alameda County deadline
- 2026 filing window
- July 2 – September 15, 2026
- Where to file
- Alameda County Assessment Appeals Board
- Form
- BOE-305-AH (Application for Changed Assessment)
- Filing fee
- $50 per parcel (non-refundable)
- How to file
- Online portal, mail, or in person
- Governing law
- Cal. Rev. & Tax. Code §1601 et seq.
✓ Fee verified on the county's official page on July 30, 2026.
Do you actually have a case?
Because of Proposition 13, homes held for a long time are usually assessed well below market value — those owners have nothing to appeal, and filing anyway costs the fee ($50 per parcel (non-refundable)) and the time. These are the three situations where an appeal is normally worth checking:
You bought near the 2022 peak and prices have fallen since
Your purchase price became the base year value. Proposition 8 requires the assessor to use the lower of that value and the market value as of January 1 — so if the market moved down after you bought, the assessment should follow it down.
You received a supplemental or escape assessment
These run on their own clock — 60 days from the date on the notice, separate from the regular July 2 – September 15, 2026 window. A recent purchase or new construction is the usual trigger.
Your base year value changed — a Prop 19 transfer, an inheritance, or a rebuild
The county sets a new assessed value on the replacement or rebuilt home. That number is the assessor's judgment, and it can be appealed like any other assessment.
California reassesses most homes only when they change hands (Proposition 13), but the assessed value on your 2026 tax bill can still be too high — especially under Proposition 8, which requires the assessor to use the lower of your factored base-year value or the property's market value as of January 1, 2026. If comparable homes around Oakland, Fremont and Berkeley sold for less than your assessed value implies, you have a case.
Appeals in Alameda County are heard by the Alameda County Assessment Appeals Board, an independent body separate from the assessor. You file BOE-305-AH (Application for Changed Assessment) during the regular filing window: July 2 – September 15, 2026. Filing fee: $50 per parcel (non-refundable).
- Alameda County mails assessment notices to all taxpayers by August 1, so its regular-period deadline is the earlier one: September 15.
How to appeal in Alameda County — step by step
- 1
Check your assessed value
Find your 2026 assessed value on the assessor's website or your value notice, and compare it against what similar homes near you actually sold for around January 1, 2026.
- 2
Gather comparable sales
Three to five sales of similar homes (size, age, neighborhood) closed near the January 1 lien date are the core of a residential appeal.
- 3
File BOE-305-AH (Application for Changed Assessment)
Submit to the Alameda County Assessment Appeals Board within the window (July 2 – September 15, 2026). Online portal, mail, or in person. Fee: $50 per parcel (non-refundable).
- 4
Keep paying your tax bill
Filing an appeal does not pause your property tax. Pay on time; if you win, the county refunds the difference with interest.
- 5
Present your case
Many counties offer an exchange with the assessor before a formal hearing. If it proceeds to a hearing, you (or your authorized agent) present the comparable sales to the board.
Is your Alameda County home over-assessed?
Everything you need to file your Alameda County appeal yourself is in the steps above. Full-service representation (we file for you) isn't available in California yet — we're expanding, and this guide lets you file on your own in the meantime.
Frequently asked questions
When is the deadline to appeal property taxes in Alameda County in 2026?
The regular filing window for a 2026 assessment appeal to the Alameda County Assessment Appeals Board runs July 2 through September 15, 2026. For supplemental or escape assessments, you instead have 60 days from the notice date.
What does it cost to file?
$50 per parcel (non-refundable). If an appeal isn't worth the fee for your situation, a free estimate tells you that before you spend anything.
Do I need a lawyer to appeal?
No. Homeowners can file and present their own appeal, or authorize an agent on the BOE-305-AH application itself. The hearing is informal — it's about sales data, not legal argument.
What if I miss the regular window?
Supplemental and escape assessments carry their own 60-day appeal window from the notice date. Otherwise you wait for next year's regular window — and a calendar reminder now beats a missed deadline later.