How to appeal a Napa County, CA property assessment
✓ Verified — Last verified October 24, 2026
Filing details published for Napa County. Match the notice and assessment cycle to the official instructions.
Official appeal instructionsNot tax or legal advice; confirm with your county.
Filing timing
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Where to file
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Official offices
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Napa County Assessor
Sources for these instructions
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Read the source quotations (10)
https://www.napacounty.gov/1415/Assessment-Appeals
Regular Assessments – Filed between July 2 and November 30 of the current year
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https://www.napacounty.gov/1415/Assessment-Appeals
The Clerk of the Assessment Appeals Board has up to two years to schedule a hearing
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https://www.napacounty.gov/m/NewsFlash/Home/Detail/889
The first installment is due November 1, 2026, and must be paid by 5 p.m. on December 10, 2026 to avoid a 10% penalty.
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https://www.napacounty.gov/m/NewsFlash/Home/Detail/889
The second installment is due February 1, 2027. Taxpayers have until 5 p.m. on April 12, 2027 to pay without a penalty because April 10 falls on a Saturday.
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https://www.napacounty.gov/m/NewsFlash/Home/Detail/889
must be paid by 5 p.m. on December 10, 2026 to avoid a 10% penalty.
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https://www.napacounty.gov/m/NewsFlash/Home/Detail/889
first installment of their 2026-2027 property taxes
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https://www.napacounty.gov/m/NewsFlash/Home/Detail/889
Robert Minahen, Napa County Tax Collector
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https://www.napacounty.gov/154/Assessment-Appeals-Process
Napa County Assessor-Recorder-County Clerk at 707.253.4459
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Continue with your property
Common questions
Where do I file a Napa County assessment appeal?
Napa County Clerk of the Assessment Appeals Board
Updated , from cited verification dates. Individual sources may have earlier checks.