California Property Tax Appeal
How to Appeal Your Property Taxes in Alameda County (2026)
Alameda County — Oakland, Berkeley, Fremont and the rest of the East Bay — has seen home values swing sharply with the Bay Area's tech cycles. When a neighborhood cools after a run-up, the assessed value on your bill can stay stuck near the peak, and that gap is exactly what an appeal exists to correct.
Two Alameda specifics are easy to trip over. The formal deadline is September 15, earlier than the November 30 many California counties use. And Alameda still requires paper applications to be filed in duplicate, with payment accompanying the application — small logistics that sink appeals when they're missed. The Assessor does offer an informal Decline-in-Value (Prop 8) review first, which is the smart opening move.
This page walks through the Alameda County process in full — the September 15 deadline, the form and its duplicate-filing rule, the fee, and the informal-first path — plus an honest read on whether your home is actually overassessed.
Alameda County appeal — at a glance
- Appeal deadline
- July 2 – September 15
- Filing fee
- $50
- Appeal form
- BOE-305-AH
- Assessor's office
- (510) 272-3787
Check your Alameda County home in minutes
Enter your address and get an honest, comparable-sales analysis of whether you're overassessed — $9.99, with 3 years of monitoring included.
Analyze my assessmentFlat fee. You keep 100% of your tax savings.
Is your Alameda County home overassessed?
California property tax bills run roughly 1.1%–1.25% of a home's assessed value. At that rate, an assessment that's $50,000 too high costs a homeowner on the order of $550–$625 every single year — and it compounds until someone corrects it.
The only way to know is to compare your assessed value against what similar nearby homes actually sold for. That's exactly what a Numa analysis does: real comparable sales, an honest overassessed / fairly-assessed verdict, and a conservative savings estimate — for $9.99, with 3 years of monitoring included.
How to appeal in Alameda County, step by step
- 1
Confirm your home is overassessed
Your case rests on recent sales of comparable homes. Gather a few similar properties nearby that sold recently, adjust for differences in size, age, and condition, and check whether they came in below your assessed value. This is the most time-consuming part of an appeal, and the quality of those comparables is what decides it.
- 2
Request an informal review with the Assessor
In Alameda County, start with an informal Decline-in-Value (Proposition 8) review — often the fastest path, resolved without a hearing. Get the informal review form.
- 3
File a formal appeal if needed
If the informal review doesn't resolve it, file form BOE-305-AH with the Assessment Appeals Board — before the September 15 deadline. You can file online, by mail, or in person.
- 4
Present your evidence
Your comparable-sales evidence is what wins the appeal. Numa's $24.99 packet assembles it into a ready-to-file case — and if the informal review fails, the formal Appeals Board packet is included at no extra charge.
Do it yourself, or let Numa do the hard part
You can absolutely appeal on your own — the deadline, form, and steps above are all you need to file. The catch is Step 1: building the comparable-sales evidence that actually wins. Here's the honest trade-off.
Do it yourself
- Free
- Typically 5–10 hours of work
- You find, adjust, and score the comps yourself
- Amateur evidence is the top reason appeals fail
- No easy way to know if you should file at all
With Numa
- $9.99 analysis, done in minutes
- Real comparable sales, scored the way the county does
- An honest verdict — including “don't file, you're fairly assessed”
- 3 years of monitoring included
- Optional $24.99 ready-to-file evidence packet if you're overassessed
Alameda County key dates
- Appeal window: July 2 – September 15
- Paper applications must be filed in DUPLICATE. Payment must accompany the application.
- Prop 8 (decline in value): Same as regular appeal deadline (July 2 – September 15). Deadline extends to September 16 if September 15 falls on a holiday/weekend.
Alameda County property tax appeal — FAQ
What is the property tax appeal deadline in Alameda County?
The regular appeal window runs July 2 through September 15. Paper applications must be filed in DUPLICATE. Payment must accompany the application.
How much does it cost to appeal property taxes in Alameda County?
The filing fee is $50.
Do I have to go to a hearing to lower my assessment?
Often not. In Alameda County you can request an informal review (a Decline-in-Value / Proposition 8 request) with the Assessor first — many reductions are resolved this way without a formal hearing. If the informal review doesn't succeed, you can file a formal appeal with the Assessment Appeals Board.
How do I know if my Alameda County home is overassessed?
Your home is overassessed if comparable homes recently sold for less than your assessed value. Numa runs that comparison for you — the same comparable-sales method the county uses — and gives you an honest verdict for $9.99, with 3 years of monitoring included.
What form do I use to appeal in Alameda County?
Formal appeals use form BOE-305-AH, filed with the Assessment Appeals Board. Numa's packet fills in the evidence and shows you exactly how to file it.
Check your Alameda County home in minutes
Enter your address and get an honest, comparable-sales analysis of whether you're overassessed — $9.99, with 3 years of monitoring included.
Analyze my assessmentFlat fee. You keep 100% of your tax savings.