California · property tax · 2027
California property tax appeal deadline 2027.
File an assessment appeal application with your county board between July 2 and September 15. The window runs to November 30 in a county that does not mail assessment notices by August 1.
Statute-based window, check your county
This page is arithmetic and a plain-English reading of the statute. It is not legal, tax or financial advice. Your county clerk of the board certifies the last day of the filing period.
Check the filing window
The California rule
Revenue and Taxation Code section 1603(b)(1) says an application for reduction of an assessment must be filed within the time period from July 2 to September 15, inclusive, and that an application mailed and postmarked by September 15 within that period is deemed filed. Section 1603(b)(3) extends the last day to November 30 for a county whose assessor does not provide, by August 1, a notice to all assessees of real property on the local secured roll of their assessed value. The county assessor tells the clerk of the county board by April 1 whether the notice will go out by August 1, and the clerk certifies the last day of the filing period. The State Board of Equalization keeps a statewide listing of each county's period.
If your notice was late
Section 1603(b)(2) lets you file within 60 days of receiving the notice of assessment, or within 60 days of the mailing of the tax bill, whichever is earlier, if you did not receive the notice at least 15 calendar days before the deadline. You must include an affidavit under penalty of perjury that the notice did not arrive on time.
Worked example
On July 2, 2027 the window opens. If your county mailed notices by August 1, the calculator's default close of September 15, 2027 applies. If your county did not, change the close date to November 30, 2027 and the countdown follows.
What the application needs
Section 1603 requires a verified, written application on the form prescribed by the State Board of Equalization, showing the facts claimed to justify a reduction and your opinion of the property's full value.
- Recent sales of comparable properties near the lien date.
- An appraisal or your purchase contract, if recent.
- Photos and repair estimates showing condition problems.
- Your notice of assessment or tax bill.
Limits of this page
- It covers the regular annual assessment. Supplemental and escape assessments have different deadlines.
- The page reproduces the statute as read; counties may publish additional filing mechanics.
- It cannot tell you which of the two windows your county uses; the clerk of the board can.
Frequently asked questions
What is the California property tax appeal deadline for 2027?
The filing period for the regular assessment runs July 2 to September 15, inclusive, or to November 30 in a county that does not send assessment notices by August 1 (Rev. & Tax. Code 1603).
How do I know whether my county uses September 15 or November 30?
The county clerk of the board certifies the last day of the filing period, and the State Board of Equalization keeps a statewide listing by county.
Is a mailed application filed on time in California?
Yes, if it is mailed and postmarked on or before the last day of the filing period.
What if I never got my assessment notice in time?
Section 1603(b)(2) allows filing within 60 days of receipt or of the tax bill mailing, whichever is earlier, with an affidavit that the notice was not timely received.
Sources
Read November 2, 2026. Figures and rules on this page come from these pages and no others; what each one could not confirm is stated above.