California Property Tax Appeal
How to Appeal Your Property Taxes in San Francisco County (2026)
San Francisco is both a city and a county, and it runs its assessment appeals a little differently from everywhere else in California. Values here are high enough that even a small over-assessment — common on condos and flats after a soft patch in the market — translates into a serious tax bill.
A few SF-specific things to know: the city uses its own appeal application (based on the state BOE-305-AH, but not identical), the formal deadline is September 15, and the informal review window for residential property runs only January 2 through March 31 each year. Miss that informal window and the formal appeal is your route. The $120 filing fee is among the state's higher ones, so it pays to know you have a real case first.
Here's how the San Francisco process works — the September 15 deadline, the city's own form, the fee, and the narrow informal window — along with an honest read on whether your home is overassessed.
San Francisco County appeal — at a glance
- Appeal deadline
- July 2 – September 15
- Filing fee
- $120
- Appeal form
- SF-AAB
- Assessor's office
- (415) 554-5596
Check your San Francisco 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.
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Is your San Francisco 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 San Francisco 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 San Francisco 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 SF-AAB 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
San Francisco County key dates
- Appeal window: July 2 – September 15
- SF is a city/county. Uses SF-specific form (based on BOE-305-AH). New informal review form issued each year. Informal review available January 2 – March 31 for residential properties.
- Prop 8 (decline in value): Informal review January 2 – March 31 (SFR, condos, townhouses, live-work lofts, cooperatives only). Formal appeal July 2 – September 15 for all property types.
San Francisco County property tax appeal — FAQ
What is the property tax appeal deadline in San Francisco County?
The regular appeal window runs July 2 through September 15. SF is a city/county. Uses SF-specific form (based on BOE-305-AH). New informal review form issued each year. Informal review available January 2 – March 31 for residential properties.
How much does it cost to appeal property taxes in San Francisco County?
The filing fee is $120.
Do I have to go to a hearing to lower my assessment?
Often not. In San Francisco 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 San Francisco 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 San Francisco County?
Formal appeals use form SF-AAB, filed with the Assessment Appeals Board. Numa's packet fills in the evidence and shows you exactly how to file it.
Check your San Francisco 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.