Riverside County Property Tax Appeal — Deadline & How to File 2026
September 15 (regular roll; window opens July 2)86 days left to file
Yes — Riverside County's 2026 property-tax appeal deadline is September 15 (regular roll; window opens July 2). 86 days left to file with the County Assessment Appeals Board.
Is my property over-assessed in Riverside County?
You're over-assessed when the County's value is higher than what your home would actually sell for — and then you're over-paying every year until you appeal. California regular-roll assessment appeals open July 2 and close September 15 in this county (because it mails value notices to all owners by August 1), per Cal. Rev. & Tax. Code §1603. A Decline-in-Value (Prop 8) review can be requested separately. Supplemental/escape assessments have their own 60-day window.
Honest null: Riverside County's assessment roll isn't onboarded into our live check yet, so we can't pull your specific over-assessment here. Compare your assessed value to recent nearby sales on the county assessor portal — if it's higher than what your home would sell for, you're over-assessed and should appeal by the deadline above.
How to appeal your Riverside County assessment — and who files it for you
Pull your current assessed value from the Riverside County assessor portal.
Find your market value — a recent sale of your home, or comparable nearby sales.
If the County's number is higher, file an appeal with the County Assessment Appeals Board by September 15 (regular roll; window opens July 2).
Present your comparables (and any appraisal) at the hearing.
Most owners who win use a contingency property-tax appeal firm — it costs nothing unless they cut your bill, then takes a share of the first-year saving. About 95% of over-assessed owners never appeal, so the saving is usually left on the table.
What is the Riverside County appeal deadline this year?
September 15 (regular roll; window opens July 2) — 86 days left.
How much does it cost to appeal?
Usually a small filing fee or none; a contingency firm only charges if it wins a reduction.
I got a reassessment notice — what now?
It's the County's new market-value opinion and the start of your appeal window. Check it; appeal by September 15 (regular roll; window opens July 2) if it over-states your home's value.
Will appealing raise my taxes?
In most jurisdictions an appeal can only confirm or lower your assessment for that cycle — but confirm the rules with the County Assessment Appeals Board before filing.
Source & verification
against the official Riverside County / CA deadline (rivcoacr.org · Cal. Rev. & Tax. Code §1603). These are public deadline facts, not legal or tax advice — confirm your exact date with the County Assessment Appeals Board and consult a professional before filing.