Alameda County, California property-tax payment and appeal deadlines
Tax bills, payment rules, and valuation-review windows are controlled by the local jurisdiction and the governing state framework. The reviewed record below separates published figures from items that still require confirmation with Alameda County Assessor's Office.
Rate context
ConfirmCalifornia property tax rates are composed of the 1% constitutional levy plus voter-approved debt and local assessments that vary by tax rate area; no single current effective countywide percentage was published in the official county sources reviewed.
Statement mailing
PublishedAnnual secured property tax bills are mailed once a year by November 1, 2026.
Payment deadline
PublishedFor the 2026-27 secured roll, the first installment is due November 1, 2026 and delinquent after December 10, 2026; the second installment is due February 1, 2027 and delinquent after April 10, 2027. If a delinquency date is a weekend or holiday, the next business day applies.
Valuation protest
PublishedRegular California assessment appeal period: July 2 through September 15, 2026 if the county assessor mailed assessed-value notices by August 1; otherwise July 2 through November 30, 2026. Supplemental or escape assessment appeals are generally due within 60 days of the notice or bill.
Do not assume a grace period.
The reviewed record identifies the payment timing above but does not establish a universal penalty schedule for this page. Late charges, interest, collection costs, tax-sale procedures, and lien or foreclosure timelines can depend on state law and the local collector’s process. If the deadline is close or a balance is delinquent, contact the tax collector directly and request the current payoff amount in writing.
Treat a published payment deadline as a hard operational date and retain your receipt or confirmation number.
From assessment to collection
01Valuation and notice
Review the assessment notice as soon as it arrives. The protest window may run from the notice date rather than from the payment due date.
02Statement and account review
Match the tax statement to the parcel or account number and confirm exemptions, assessed value, taxing units, credits, and balance.
03Payment confirmation
Use the official collector channel, then save the receipt, transaction reference, and date posted. A bank submission is not always the same as a county posting date.