How to Appeal Your San Francisco Property Taxes: Step-by-Step
By Danielle Cui · February 4, 2026
If you've felt the pinch of a hefty property tax bill while your home's value has slipped, you don't have to just accept it. Appealing an over-assessed San Francisco property is more accessible than most homeowners think. Here's the whole process, end to end.
How property taxes are calculated
Your property tax bill is based on your assessed value, which is supposed to reflect market value. Thanks to Proposition 13, the assessed value can't rise more than 2% per year unless there's a change in ownership or new construction. (For why that cuts against you in a down market, see Prop 13 & Prop 8 explained.)
- Assessed value: the value the county assessor places on your property for tax purposes.
- Market value: what your property would actually sell for today.
When the market is hot these track closely. When values fall, a gap opens — and that gap is money out of your pocket.
Step-by-step
1. Check your eligibility. Compare your assessed value to current market value. Do not rely on a Zillow "Zestimate" — assessors don't accept it as evidence. You need actual sales of comparable properties (comps) in the right window. A common trap: people check Zillow in September, five months after the comp window has closed, and get a misleading number.
2. Gather documentation. You'll need the appeal application, evidence of market value (recent comparable sales), and optionally a professional appraisal. See the evidence that actually wins.
3. Complete the application accurately. Fill out every section; simple errors cause delays or denials.
4. Submit before the deadline. San Francisco's regular filing window runs July 2 to mid-September (September 15 in most California counties — confirm the exact date each year on the Assessment Appeals Board site). Late applications aren't accepted. See the full deadline & timeline.
5. Prepare for the hearing. Organize your evidence into a clear, concise presentation and practice explaining why your market value is lower.
6. Attend the hearing. You present to the Assessment Appeals Board. It's far less formal than court, but professionalism counts — here's what to expect.
7. Await the decision. The board mails its decision; if successful, your assessment — and bill — are adjusted.
How much can you save?
Savings scale with the reduction. As a rough rule in California, every $100,000 knocked off your assessed value is about $1,200/year in tax. A consultant who takes the case typically charges ~35% of the savings; doing it yourself (or with a tool) keeps that.
Avoid the common mistakes
- Missing the deadline — late applications won't be considered.
- Weak or out-of-window comps — sales after the ~April 1 cutoff (90 days past the January 1 lien date) can't be used.
- Form errors — double-check everything before submitting.
You don't need a lawyer. You need the right comps, in the right window, presented clearly — which is exactly what CompFinder assembles for you.
Frequently asked questions
How often can I appeal my property tax assessment?
You can appeal once per assessment year.
Can condo owners appeal their property tax assessments?
Yes. Condo owners have the same appeal rights as any other property owner.
Can I appeal my property taxes online?
San Francisco accepts online appeals. Some other jurisdictions still require mail or in-person filing — check your county's Assessment Appeals Board.
How does Proposition 13 affect property tax appeals?
Prop 13 caps annual assessed-value increases at 2% but does not prevent reductions. In a down market you can seek a temporary reduction through a Proposition 8 appeal.
Will appealing affect my future assessments?
A successful appeal adjusts your assessed value for the current year. Future increases are still subject to Prop 13's 2% annual cap.
Is there a risk my property taxes could increase if I appeal?
It's rare. The worst common outcome of a market-decline appeal is that your assessment stays the same.
What if I recently purchased my property?
Your recent purchase price is strong evidence of market value. If you bought below the assessed value, you have a solid case.