Why did my property tax go up when my home value went down?

Proposition 13 caps annual assessed-value increases at 2% but doesn't require reductions when the market falls. Assessments also don't auto-adjust downward, so your bill can stay high — or rise ~2% — until you file a Proposition 8 appeal.

What is a Proposition 8 appeal?

A Prop 8 appeal requests a temporary reduction in assessed value when your property's market value has fallen below its assessed value. When the market recovers, the assessed value can rise back toward the original Prop 13 base.

Does the assessor automatically lower my assessment in a down market?

No. The Assessor's Office generally does not proactively reduce assessments for market declines. You have to request it by filing an appeal.

Will appealing trigger an audit or higher taxes later?

Generally no. The appeal process is designed to ensure fair assessments, and the worst common outcome is that your assessment stays the same.

Why SF Property Taxes Stay High When Values Drop (Prop 13 & Prop 8)

Buy a condo, watch its value slide, and then open a tax bill that's higher than last year's — how? It's not a glitch. A few features of California property tax law keep bills inflated in a down market. Here's what's actually going on.

Proposition 13: the double-edged sword

Prop 13 (1978) caps the annual increase of a property's assessed value at 2%, no matter how much the market rises. Great protection in a boom. The catch: when the market declines, Prop 13 doesn't require the assessed value to come down. So unless you act, your assessed value — and your bill — can stay high and even tick up ~2%.

Proposition 8: your temporary lifeline

Prop 8 (also 1978) allows a temporary reduction when market value falls below assessed value. The key word is temporary: once the market recovers, the assessed value can rise by more than 2%/year until it catches back up to the original Prop 13 value.

The hidden part: no automatic downward adjustment

Here's what trips up most homeowners: the Assessor's Office does not automatically lower your assessed value when the market dips — they don't have the resources to proactively reassess every property each year. It's on you to request a Prop 8 reduction (i.e., to appeal). File early enough and an appeal for one year can shape the next year's bill, too.

Why assessments lag the market

San Francisco's market — condos especially — has been volatile, pushed by remote-work shifts, economic uncertainty, and more. Because assessments don't auto-adjust for declines, there's a real lag between what's happening in the market and what's on your bill. Unless you proactively file, your taxes may not reflect today's reality.

What to do about it

Review your assessment annually. If your neighborhood has declined, your assessment may be stale.
Pull real comps near the January 1 valuation date — not Zillow estimates. (How to choose comps that win.)
File within the window (July 2 to mid-September). (Deadline & timeline.)
Present your case — it's more approachable than you'd think. (Step-by-step · what the hearing is like.)

The system isn't designed to refund you automatically. But the worst common outcome of appealing a market-decline assessment is that nothing changes — and the upside is often thousands a year, compounding into future bills. Don't leave it on the table.