Appealing Your SF Property Assessment: Review vs Formal Appeal

If comparable homes sold for less on January 1 than your assessed value, you are owed a lower tax bill for that year, and getting it is free. San Francisco's Assessor runs an informal review each winter; the formal appeal to the Assessment Appeals Board costs a small filing fee and an afternoon. Nobody needs to take a large share of your savings to pull five comps. Here is when an appeal makes sense, how both routes work, what evidence wins, and how the reduction behaves afterward.

When an appeal makes sense

There are two different arguments, and you should know which one you are making.

Decline in value (Prop 8). Your factored base-year value, set at your purchase price and growing up to 2% a year, is higher than what the home would sell for on January 1 of this year. State law says you pay tax on the lower of the two. This is the common case for anyone who bought near a peak, and it is an annual question: each January 1 is a fresh test.

Challenging the base-year value itself. You believe the Assessor set the wrong value when you bought, for example by enrolling more than your purchase price, or by adding too much for new construction. This is a permanent correction rather than a temporary one, and it must be raised within a limited window of years after the value is first enrolled.

A quick test before anything else: pull closed sales of similar homes from the months around January 1 in the comps tool and compare them with the value on your summer notice. If the comps cluster 5% or more below your assessed value, the paperwork is worth it. At SF's 1.1827% rate, a $100,000 reduction saves about $1,180 for the year.

Step one is free: the Assessor's informal review

Each year the Assessor-Recorder accepts informal review requests for residential property in the opening months of the year, for the value as of January 1. You fill in a short form, attach your comparable sales, and the Assessor's staff decide whether to enroll a lower value before the notices go out in the summer. No hearing, no fee.

What to send:

• Three to five closed sales from roughly October through March, closest to January 1, with address, sale date, price, square footage, bed and bath count, parking and unit type.
• A one-page summary showing each comp, your adjustments, and your conclusion of value next to the assessed value.
• Photos and written bids for any condition problems that a buyer would price in: foundation, roof, dry rot, an unfinished retrofit.

The 2026 window ran January 2 through March 31; as of 2026-10-25, confirm the next window on the Assessor's site. If the Assessor agrees, your bill falls for that year. If not, or if no answer arrives before July, move to step two; the informal review does not extend the formal deadline.

Step two: the formal appeal

The Assessment Appeals Board is independent of the Assessor. You file an Application for Changed Assessment:

The filing fee is $120 per application as of 2026-10-25 (it was $60 before August 2025), plus a small convenience fee for online filing; check the Board's site for the current amount. Residential owners can request a single hearing officer, which is faster than the full Board. The Board has two years from filing to decide, and if it misses that deadline your opinion of value is generally enrolled, so file complete paperwork. One rule catches people: keep paying the bill on time while the appeal is pending. A win comes back as a refund with interest; a missed installment carries a 10% penalty whatever the outcome.

For an owner-occupied single-family home or condo, state law puts the burden of proof on the Assessor at the hearing, which is a meaningful advantage when your evidence is organized.

Building your evidence as of January 1

The valuation date is January 1 of the fiscal year you are appealing, and the Board can consider sales up to 90 days after that date.

• Use closed sales, not listings. List prices in SF are set low on purpose; a listing proves nothing. Why list prices are low explains the mechanism.
• Match the home. Same unit type (condo, TIC share, house), similar size, similar era, same parking situation, same part of the city. A view unit and an interior unit in the same building are not comps.
• Adjust and show your work. Price per square foot, then adjustments for condition, parking, outdoor space and HOA dues. Reading comps covers the method; it is the same analysis you did to buy, run in reverse.
• Document condition. Contractor bids, inspection reports and photos dated near January 1 support a deduction for repairs a buyer would require.
• Do not cite neighbors' assessed values. Under Prop 13 they reflect purchase dates, not market value.
• An appraisal is optional. A retrospective appraisal as of January 1 helps a complex property and is unnecessary for a standard condo with five clean comps.

The comps tool shows closed sales around any SF parcel with the comps toggleable, which is exactly the exercise: keep the sales a Board member would accept and drop the rest.

What happens at the hearing

You and an Assessor's appraiser each present evidence and answer questions; the hearing officer or Board sets the value, which can be yours, the Assessor's or a number in between. Bring three copies of everything and a one-page summary, and request written findings of fact beforehand only if you intend to take the matter further. Outcomes track the evidence: a documented Prop 8 appeal with recent closed sales usually produces some reduction; a listing printout and a feeling usually does not.

Prop 8 reductions are temporary

A decline-in-value reduction applies to one fiscal year. Each January 1 the Assessor compares market value with your factored base-year value again:

Notice year 3 to year 4: taxable value jumped 7.7%, far more than 2%, because the 2% cap applies to the factored base-year value, not to a temporary Prop 8 value climbing back toward it. A reduction never lowers your base-year value and never costs you later; it only saves you in the down years. SF's Assessor reviews some reductions proactively, but you should submit an informal review request every January the market remains below your base.

Appeal services: what they do and when DIY is obvious

Contingency firms file the same form with the same comps and charge a share of the first-year saving, often a large one. For a standard SF condo or house with a Prop 8 argument, do it yourself. Hire help for a base-year dispute involving new construction or a non-market transfer, a property with severe damage or a legal cloud, or a multi-unit building where the income approach matters; there a flat-fee appraiser or an attorney who appears before the Board regularly beats a percentage firm.

What to shop for right now

Little, and that is the point. The informal review is free and the formal appeal costs a modest filing fee. If a case is complex enough to need a professional, compare a flat-fee retrospective appraisal with a contingency firm's percentage, and put the fee terms in writing. This site earns nothing from any of it; it is paid through the buyer-side commission only if you later work with one of its agents on a purchase.

Mistakes that get appeals denied

• Filing after September 15, or after the 60-day supplemental window.
• Using sales from the wrong year, or from more than 90 days after January 1.
• Submitting list prices, online estimates or neighbors' tax bills as evidence.
• Not paying the bill while the appeal is pending.
• Skipping the hearing. An applicant who does not appear usually loses by default.
• Assuming last year's reduction carries forward automatically.

Keep a folder with each year's notice, your comps and the outcome. The supplemental tax bill you paid in year one documents your base; the exemption and Prop 13 article explains the value you are measuring against.