Lower your Alameda County property taxes
The Alameda County Assessor sets your value each January 1, and the formal appeal window closes September 15. Each appeal carries a nonrefundable $50 fee, so the evidence needs to be right the first time. 30% of first-year savings, only if you save.
What a too-high value costs you
If your home is assessed at $1,150,000 but similar homes point to about $1,060,000, you're taxed on $90,000 too much. At a 1.23% rate that's about $1,107 a year. Our fee would be $332; you'd keep $775.
What gets missed in Alameda County
- The early deadline. Appeals close September 15 at 5:00 p.m. here, not November 30. You can file to November 30 only if you didn't get a value notice before August 1.
- Late comparable sales. For a January 1 value, sales must close by March 31. Later sales are not accepted.
- Size mismatches. ADUs, in-law units and additions are recorded wrong or compared with the wrong homes.
- Wrong comparisons. Hills and flatland sales in the same city are not the same market.
Insider tip: You can ask the Assessor for an informal review outside the appeal window. Write "INFORMAL REVIEW" on the envelope and leave plenty of time before September 15.
Reviewed by the founder
Julien reviews every Alameda County case personally and tells you the value we’ll ask for before anything is filed.
Get my free reviewAlameda County calendar
| January 1 | Valuation date for the 2027–28 roll |
| March 31 | Last day for sales that can support a January 1 value (90 days) |
| July 2 – September 15, 2027 | Formal appeal window with the Assessment Appeals Board ($50 per parcel), 5:00 p.m. deadline |
| At least 45 days before | Hearing notice mailed |
| Within 2 years of filing | Board must decide unless you sign a waiver to extend |
| December 10, 2027 / April 10, 2028 | First / second tax installment delinquent if unpaid |
Sources: Alameda County Assessment Appeals Board — 2026 information booklet · BOE LTA 2026/023 — filing periods · BOE — Homeowners' exemption. Dates are checked each year; confirm with the county for your property.
Exemptions to check
The homeowners' exemption takes $7,000 off the taxable value of your main home; file Form BOE-266 by February 15 for the full amount. Disabled veterans may qualify for a much larger exemption, and Prop 19 lets owners 55 and over move their tax base. We check your exemptions free at sign-up.
Alameda County questions
Is there a fee to appeal in Alameda County?
Yes. A nonrefundable $50 processing fee per application (one per parcel), paid by certified check or money order.
How do I file?
With the Clerk of the Assessment Appeals Board, through its online portal with electronic signature, or by mail or in person.
I missed September 15. Now what?
Sign up anyway. We can request an informal review with the Assessor and file in the window that opens July 2, 2027.