San Mateo County, California
Filing deadline: November 30 (earliest possible)
The deadline for filing an Assessment Appeal is November 30. If the county Assessor does not mail assessment notices to all taxpayers by August 1, the filing period is extended to November 30 instead of September 15 (California Revenue & Taxation Code Section 1603).
What to file
appeal
Approximate effective tax rate
1.26% (published estimate, 2025)
County filing fee
$30
Look up your current assessed value on the county assessor's site →