Is the California property tax appeal deadline September 15 or November 30?

California's appeal deadline depends on your county. Under Cal. Rev. & Tax. Code §1603, the regular filing period opens July 2 and closes on one of two dates:

• September 15 — in counties where the assessor mails an assessed-value notice to all owners of real property on the local secured roll by August 1.
• November 30 — in counties where the assessor does not provide that notice to all owners by August 1.

The statute reads that the filing period runs "from July 2 to September 15, inclusive," and that "the last day of the filing period shall be extended to November 30" when the August 1 notice condition is not met. Per the state BOE assessment appeals page, most California counties fall into the November 30 group; a minority — including several large urban counties — use September 15.

Practical points:

• Confirm your county's date every year. A county can switch between the two dates annually depending on its notice practice, so do not assume last year's deadline. The clerk of the board or the county's appeals page publishes the current period.
• Weekend/holiday rule. If the final date falls on a Saturday, Sunday, or legal holiday, an application postmarked the next business day is timely.
• Supplemental and escape assessments have their own 60-day clocks that run independently of the July–November regular period.

Missing the deadline generally forfeits your formal appeal for that roll year, so file the BOE-305-AH early.