The Evidence You Need to Win an SF Property Tax Appeal

If you've watched your home's value ride a rollercoaster, you may be overpaying property tax. The way you prove it is evidence — and in San Francisco, the evidence that matters most is comparable sales.

Understanding your current assessment

You've likely received a notification from the Assessor-Recorder's office. Thanks to Prop 13, your assessed value isn't necessarily what you paid — it's either the purchase price (if you bought recently) or the base-year value plus up to 2% per year. (Why that keeps bills high in a down market.)

1. Comparable sales — your strongest evidence

Nothing speaks louder than what similar homes actually sold for. To pick comps that hold up:

• Sale date: as close to the January 1 valuation date as possible. Per California Rev. & Tax Code §402.5, a sale dated more than 90 days after the valuation date (i.e., after ~April 1) cannot be admitted as a comparable.
• Location: prioritize your immediate neighborhood — ideally your own building or block.
• Property-type match: condo to condo, house to house — never mix.
• Size: similar square footage. A 500 sq ft studio doesn't compare to your 1,500 sq ft two-bedroom.
• Beds & baths: match as closely as possible.
• Age & condition: built around the same time, in similar shape. A 1980s building isn't comparable to a brand-new luxury high-rise.
• Amenities: parking (huge in SF), storage, views, building amenities, upgraded interiors.
• Floor level: for high-rises, compare similar floors — a 3rd-floor unit isn't a 30th-floor unit with sweeping views.
• Arms-length only: no foreclosures, short sales, family transfers, or auction sales.
• Views: in SF, views move value a lot — match view quality.

Pro tip: build a simple table comparing your home to 3–5 qualifying sales (address, sale date, price, sqft, bed/bath, floor, parking, views, features), and note how you confirmed each was arms-length. No comp is perfect; the closer you match on each factor, the stronger your case. This comp research and analysis is exactly what CompFinder does for you in seconds instead of hours.

2. Market-trend analysis

Show the board you understand the broader market: cite reputable neighborhood data, and for your chosen comps note days-on-market and any discount from list price.

3. A professional appraisal (when it's worth it)

For high-value or complex cases, a formal appraisal can help if the board deems it reliable. Note the board may require the appraiser to attend the hearing; depositions aren't admissible.

Putting your case together

• Write a clear, concise summary of why your assessment is too high.
• Organize comps, condition documentation, and market analysis into one tidy package.
• Practice explaining it plainly — then take it to the hearing.

And don't miss the filing window — review the deadline and timeline before you start.