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How do I appeal my property tax assessment?

County Assessor (informal review) / Assessment Appeals Board (formal appeal) / California State Board of Equalization (oversight)
Step by Step

How to do it

  1. Understand California's assessment system first:
  2. - Proposition 13 BASE YEAR APPEAL: If you recently purchased property or completed new construction and believe the County Assessor enrolled an unfairly high base year value - this appeal challenges the base year value permanently
  3. - Proposition 8 DECLINE IN VALUE APPEAL: If your property's current market value (as of January 1 of the tax year) is lower than its assessed Prop 13 value - you can request a temporary reduction; must re-file annually as long as market value remains depressed
  4. Contact the County Assessor informally first - most counties offer an informal review process before formal filing
  5. Obtain the Assessment Appeal Application from your County Clerk or county website (each county has its own form)
  6. File the application with your County Assessment Appeals Board within the filing window:
  7. - Most counties: July 2 - November 30
  8. - 11 counties (Alameda, Alpine, Inyo, Kings, Mono, Placer, San Francisco, San Luis Obispo, Santa Clara, Sierra, Ventura): July 2 - September 15
  9. - Supplemental/Escape assessments: 60 days from notice mailing date
  10. - Calamity reassessments: 6 months from notice date
  11. NO EXTENSIONS AVAILABLE
  12. Gather supporting evidence: comparable sales data (as of January 1 of the tax year), recent appraisal, photos, factual errors on property record
  13. Attend Assessment Appeals Board hearing (typically scheduled 3-6 months after filing); present your evidence
  14. Receive the Board's written decision
  15. If unsatisfied: appeal to California Superior Court
Details

What you need to know

Required Docs
  • Completed Assessment Appeal Application (county-specific form)
  • Supporting evidence: comparable sales as of January 1, recent appraisal, photos, factual documentation
  • Assessor's Parcel Number and current assessed value
Fee
No fee for Assessment Appeals Board filing in most counties; some large counties charge a filing fee; Superior Court appeal involves court filing fees FILING WINDOW: July 2 - November 30 (most counties) or July 2 - September 15 (11 specific counties) - no extensions HEARING TIMELINE: Typically 3-6 months after filing; some counties have backlogs of 1-2 years ONLINE OPTION: Some counties accept online applications (check your county's Assessment Appeals Board or County Clerk website) WHERE TO GO: County Assessment Appeals Board (file with County Clerk in most counties); find your county's board at boe.ca.gov
Online Option
Some counties accept online applications (check your county's Assessment Appeals Board or County Clerk website)
Where to Go
County Assessment Appeals Board (file with County Clerk in most counties); find your county's board at boe.ca.gov
County-specific variations apply

Filing deadlines differ between the 11 September 15 counties and the remaining 47 November 30 counties - verify your specific county's deadline immediately. Application forms, filing procedures, and hearing wait times vary significantly by county. LA County has the largest appeals board operation and longest wait times; smaller counties process appeals faster. Some counties accept online filing; others require in-person or mail submissions.

California Notes

Important state-specific details

  • California's Proposition 13 system means most long-time owners are already paying taxes well below market value - Prop 13 base year appeals are rare. Most California appeals are Prop 8 decline-in-value reviews for recent buyers or during market downturns.
  • Prop 8 reductions are TEMPORARY - the assessor reviews the value annually and can restore it (faster than 2%) as market values recover, up to the Prop 13 capped base year value.
  • Comparable sales evidence must be as of January 1 of the tax year (the lien date) - not current market data.
  • Homeowners' Exemption ($7,000 assessed value reduction) - apply separately at County Assessor; not related to appeal.
  • Property Tax Postponement Program for seniors/disabled: sco.ca.gov/ardtax_prop_tax_postponement.html
  • Disabled veterans' exemption: up to $150,000+ assessed value exempt - contact County Assessor.
Official Source

State office contact

State Office
California State Board of Equalization (assessment appeals guidance) - boe.ca.gov/proptaxes/asmappeal.htm | (800) 400-7115