San Francisco property tax in 2026 starts with Proposition 13: a 1% base rate on assessed value, plus voter-approved bonds that bring the city's total secured rate to approximately 1.18% for FY 2025-26. Your assessed value resets to the purchase price when you buy, then grows at most 2% per year.
If you're buying in San Francisco in 2026, the property tax figure that matters is not the seller's current bill. It's your purchase price. The moment the deed records, the city resets the property's assessed value to what you paid, and every line of the tax math flows from that number.
I'm Chris Chour, founder/broker of EON Real Estate. Most of my work is single-family and condo transactions in SF's luxury neighborhoods. The first question I get after an offer is accepted is some version of "what will my taxes actually be," and the honest answer has four moving parts: the base rate, the voter-approved add-ons, the one-time supplemental bill and, on some newer condos, a special-tax line many buyers have never heard of.
Unless otherwise noted, all market figures in this guide are from MLS data; the tax rules cite the agency that publishes each of them. If you're earlier in the process, the first-time buyer guide covers the full purchase sequence. This article is the tax math, worked end to end.
The rules: Prop 13 sets the frame
California property tax runs on Proposition 13, the 1978 measure codified as Article XIII A of the California Constitution (State Board of Equalization). It fixes the statewide base rate at 1% of assessed value. That is an ad valorem tax (charged as a percentage of the property's assessed value), and the assessed value, not the market value, is what every bill is computed from.
Cities and counties then add voter-approved debt service on top of the 1% base. In San Francisco, those bond add-ons bring the total secured rate to approximately 1.18% of assessed value for FY 2025-26, per the SF Treasurer & Tax Collector. The exact composite rate is set annually and runs just over 1%, so treat 1.18% as the planning number rather than a constant.
While you own, Prop 13 caps the growth of your assessed value at 2% per year, no matter how fast market value climbs (State Board of Equalization). Over a long hold, the gap between what a property would sell for and what it is taxed on can widen year after year, which is why long-held San Francisco homes often carry tax bills far below what the next buyer will pay.
Two events reset that math: a change of ownership or new construction, such as an addition (SF Assessor-Recorder). Reassessment is driven by recorded sales and building-permit records, not routine interior inspections. When ownership changes, the Assessor establishes a new base-year value equal to the purchase price, which is why the new owner's bill is usually higher than the seller's was.
San Francisco property tax by the numbers
Which bills you'll actually get: a decision tree
Three bills you might receive, then three relief valves. Work down the list in order and you'll know exactly where a given property lands.
The annual secured bill, in two installments
The fiscal year splits into two installments (SF Treasurer & Tax Collector). The first covers July 1 through December 31; it is due November 1 and goes delinquent after December 10. The second covers January 1 through June 30; it is due February 1 and goes delinquent after April 10. Miss either date and a 10% penalty attaches to that installment, with further costs accruing if it remains unpaid.
The supplemental bill after you buy
A supplemental assessment is the Assessor's catch-up bill. After a purchase, the SF Assessor-Recorder bills the difference between the seller's prior assessed value and your new purchase-price base, prorated for the remainder of the fiscal year. It arrives separately from, and on top of, the regular annual bill. The size of the bill tracks one thing: the gap between the seller's assessed value and your purchase price.
Mello-Roos: the special-tax line on newer condos
Mello-Roos is shorthand for a Community Facilities District, created under a 1982 state law that lets a district levy an additional special tax to fund and maintain local public facilities (State Board of Equalization). It sits on top of the 1%-base ad valorem tax. San Francisco's named districts include CFD 2014-1 in Transbay, CFD 2016-1 on Treasure Island, STD 2020-1 at Mission Rock and the OCII districts in Mission Bay and Hunters Point Shipyard/Candlestick (SF.gov Special Tax District Reports). The special tax appears as a line item on the secured bill, which is why two otherwise-similar condos can carry very different total taxes.
Prop 8: when the market falls below your assessed value
Proposition 8, also from 1978, requires the Assessor to enroll the lower of two numbers as of each January 1 lien date: the Prop 13 factored base-year value or the current market value (SF Assessor-Recorder). If the market has dropped below your assessed value, you can request a decline-in-value review to lower the assessment and the bill. The reduction is temporary; it lasts until values recover.
Prop 19: taking a low tax base with you
Effective April 1, 2021, Proposition 19 lets eligible homeowners transfer the factored base-year value of their principal residence to a replacement home anywhere in California (State Board of Equalization). Eligibility covers owners age 55 and over, the severely and permanently disabled, and victims of a wildfire or declared disaster; it replaced the old Prop 60/90 same-county limits and can be used up to three times. The value math matters. Buy at equal-or-lesser value and the base transfers unchanged; the threshold is 100% of the original home's value if you buy before selling, 105% within the first year after, 110% within the second. Pay above the threshold and the difference is added to your transferred base. The replacement must be bought or built within two years of the sale. This is how a longtime owner with a low Prop 13 assessment can sell and relocate without resetting to market value; owners weighing where that replacement should be can start with how to choose the right San Francisco neighborhood.
Appeals: the July 2 to September 15 window
If you believe the assessed value overstates what the property would sell for, there are two tracks. The informal track is the Prop 8 decline-in-value review through the Assessor. The formal track is an Application for Changed Assessment filed with the SF Assessment Appeals Board, an independent body rather than part of the Assessor's office; San Francisco's regular filing window is July 2 through September 15 (SF Assessment Appeals Board). Appeals are won on evidence of market value: comparable sales of similar nearby homes around the January 1 lien date. Assembling that comp set is the same work I do to price listings, and some owners refile every year they believe the roll value sits above market.
What this looks like in practice: year-1 math on a median purchase
Take a purchase at the citywide median. Over the trailing 12 months, the median closed sale on the San Francisco MLS is $1.82M ($1,822,500 exactly). Here is the year-1 arithmetic on that price:
- Base tax: 1% of $1,822,500 is $18,225, under the Prop 13 base rate (State Board of Equalization).
- Total secured bill: at the FY 2025-26 composite rate of approximately 1.18%, the annual bill lands near $21,500 (rate per SF Treasurer & Tax Collector).
- Installments: that splits into two payments of roughly $10,750 each, delinquent after December 10 and April 10.
- Supplemental: on top of the annual bill, the Assessor bills the prorated difference between the seller's old assessed value and your new $1,822,500 base for the remainder of the fiscal year (SF Assessor-Recorder).
I run this exact math with buyers before they write an offer, because the annual carry is what decides whether a stretch price is actually sustainable. The citywide numbers behind that median are in the San Francisco housing market report for Q2 2026.
Common mistakes and what to watch out for
Budgeting off the seller's bill. The seller's bill reflects their Prop 13 base, capped at 2% growth per year; yours resets to your purchase price at closing (SF Assessor-Recorder). On a long-held home the difference can be large, and it shows up in your first full bill, not years later.
Forgetting the supplemental bill. This is the one I see catch buyers most often. It arrives separately from the regular installments (SF Assessor-Recorder), so confirm with your lender whether your escrow account covers it or you are paying it directly.
Skipping the special-tax check on newer condos. In Transbay, Mission Bay, Treasure Island, Mission Rock and Hunters Point Shipyard/Candlestick, pull the actual secured bill before you write the offer (SF.gov Special Tax District Reports). The Mello-Roos line changes the carrying cost between two otherwise-similar units.
Missing the appeal window. San Francisco's regular filing period runs July 2 through September 15 (SF Assessment Appeals Board). If the market has moved below your assessed value, Prop 8 relief exists, but nobody files it for you.
How much is property tax in San Francisco in 2026?
For FY 2025-26, San Francisco's total secured property tax rate is approximately 1.18% of assessed value, per the SF Treasurer & Tax Collector. That combines the 1% Proposition 13 base with voter-approved bond add-ons; the exact composite is set each year. On a purchase assessed at the citywide median of $1.82M (MLS), that works out to roughly $21,500 a year.
Does Prop 13 still apply in San Francisco in 2026?
Yes — in 2026, Proposition 13 still governs every San Francisco property tax bill as Article XIII A of the California Constitution (State Board of Equalization). It fixes the base rate at 1% of assessed value and caps assessed-value growth at 2% per year while ownership stays the same. A sale resets the math: assessed value becomes the purchase price, per the SF Assessor-Recorder.
What is a supplemental property tax bill in San Francisco?
It's the one-time catch-up bill most 2026 buyers don't budget for. After a purchase, the SF Assessor-Recorder issues a supplemental assessment for the difference between the seller's prior assessed value and your new purchase-price base, prorated for the remainder of the fiscal year. It arrives separately from, and on top of, the regular annual bill, so plan for both in year one.
Can you appeal a San Francisco property tax assessment?
Yes — for 2026, San Francisco's regular appeal window is open now: July 2 through September 15, per the SF Assessment Appeals Board. It's an independent body, not the Assessor. You can first request an informal Proposition 8 decline-in-value review; if the Assessor declines, you can formally file an Application for Changed Assessment. Appeals are won on evidence: comparable sales near the January 1 lien date supporting a lower value.
What is Mello-Roos and does it apply in San Francisco?
Yes, in parts of the city as of 2026: some newer San Francisco developments sit inside a Community Facilities District ("Mello-Roos") that levies an extra special tax on top of the regular property tax (SF.gov Special Tax District Reports). Named districts include Transbay, Treasure Island, Mission Rock, Mission Bay and Hunters Point Shipyard/Candlestick. The charge appears as a line item on the secured tax bill, so always read the actual bill.
Talk to me about San Francisco property tax
If you're pricing a purchase and want the year-1 tax math on a specific address, including the supplemental proration and any special-tax line, I can run it alongside the comp set. And if your current assessed value sits above what the market says, the appeal evidence is the same comp work; the regular filing window closes September 15.
