SF Property Tax Lookup Guide: Assessor, DBI Permits & Bills

Looking up a San Francisco property tax bill takes about two minutes once you know where to click. This guide walks you through the official SF Tax Collector portal, explains how Proposition 13 sets your base assessment, and shows you how to find the supplemental tax bill that catches almost every new buyer off guard. ## 1. The fastest way to look up an SF property tax bill San Francisco's official portal is the SF Treasurer & Tax Collector property tax lookup at sftreasurer.org. You can search by: - Property address (e.g. "1234 Fillmore St") - Block and lot number (BLN) — printed on every preliminary title report - Assessor parcel number (APN) Once you load a property you'll see the current year's secured tax bill, payment status, the assessed value the bill is calculated against, and the breakdown of where the money goes (general fund, school bonds, voter-approved bonds, special districts). If you only have an address, you can also confirm the block/lot through the SF Office of the Assessor-Recorder's Property Information Map. ## 2. How San Francisco property taxes are actually calculated California's Proposition 13 (passed in 1978) caps property taxes at roughly **1% of assessed value**, plus voter-approved bonds and special assessments. In San Francisco the effective rate runs about **1.17% to 1.20%** of assessed value in most years once school and infrastructure bonds are added in. The critical piece for buyers: **assessed value resets to the purchase price the moment you close**. If a long-time owner is paying tax on a $400,000 assessment from 1995 and you buy the home for $1.8M, your new bill is calculated on $1.8M — not $400K. Sellers' Zillow-style "estimated taxes" are almost always wrong for the next owner. After the reset, Prop 13 limits annual increases to 2% or the rate of inflation, whichever is lower. That's why next-door neighbors with identical homes can pay wildly different bills. ## 3. Supplemental tax bills — the one most new buyers miss When the assessor catches up to your purchase (usually 3–9 months after closing), they issue a **supplemental tax bill** for the difference between the prior owner's assessment and your purchase price, prorated from your close date through June 30. This bill is **not** held in your impound/escrow account by your lender. It arrives directly in your mailbox and is your responsibility to pay. Skipping it triggers a 10% penalty plus monthly interest. Look it up the same way as your regular bill on sftreasurer.org — supplemental bills appear as a separate line item once issued. ## 4. Key dates every SF homeowner should know - **November 1** — first installment of the secured tax bill becomes due - **December 10** — first installment becomes delinquent (10% penalty after this) - **February 1** — second installment due - **April 10** — second installment delinquent - **July 1** — start of the new tax year; new assessed value takes effect - **August** — most supplemental bills issued for recent purchases ## 5. Estimating your tax bill before you make an offer Multiply your expected purchase price by **1.18%** for a reliable San Francisco estimate. On a $1.5M condo, that's roughly $17,700/year, or about $1,475/month — a number worth folding into your monthly payment math alongside HOA dues and insurance. Try our [Buyer Buying Power Calculator](https://buy.christopherleesf.com/) to see how property tax changes your maximum offer price, or the [Seller Net Proceeds Calculator](https://sellernet.christopherleesf.com/) if you're on the other side of the trade. ## 6. When to appeal your assessment If San Francisco's market drops and your assessed value is now higher than what the home would sell for, you can file a **Decline-in-Value (Prop 8) appeal** with the Assessment Appeals Board between July 2 and September 15 each year. The reduction is temporary — your assessment can climb back up (without the 2% cap) once the market recovers, but never above your original Prop 13 base. ## Questions about your specific property? Every San Francisco purchase has tax wrinkles — transfer tax, supplemental timing, exemption eligibility, and how to structure the bill so it doesn't surprise you in month four. [Reach out](/contact) and I'll walk you through the numbers for the exact property you're considering.