California Property Tax Appeal Guide
Under Proposition 13, California caps assessed value at the acquisition base year plus up to 2% annual growth, though value can be lowered when market value drops below that base.
100%
Statutory percentage
July 2 – November 30 (most counties); September 15 (San Francisco)
Verified July 2026 — confirm on your notice
Cal. Rev. & Tax. Code § 1603 (Proposition 13)
Governing state code
How to File in California
Compare your assessed value on the annual notice to your Proposition 13 base-year value.
Request an informal review with the county assessor (Prop 8 decline-in-value) first.
File an Application for Changed Assessment with the county Assessment Appeals Board (Sept 15 - Nov 30).
Prepare comparable sales as of the January 1 lien date to prove market value.
Present evidence at the Assessment Appeals Board hearing.
Deadlines and ratios vary by county and change over time — always confirm with your local assessor. This is general information, not legal advice.
Are you actually over-assessed in California?
Check this property against recent comparable sales for $4.99. If the evidence says you have no case, you know that before you spend a filing deadline on it — and if it does, the same $4.99 is credited toward the full appeal packet.
California County Guides
County-specific deadlines, forms, assessor contacts, and filing steps.
A worked example in California
Say the assessor values your home at $400,000, but comparable sales show it is really worth $350,000 — a $50,000 over-assessment. California taxes the full market value, so the taxable amount drops by the same amount. At a typical effective rate of ~1.5%, that is about $750 back in your pocket every year until the value is corrected.
Illustration only. Your actual rate, exemptions, and savings depend on your county and taxing districts — run your own numbers.
Common grounds for a California appeal
Over-market valuation. Comparable sales of similar nearby homes closed below the value the assessor placed on yours.
Errors in the property record. The county has the wrong square footage, bedroom or bathroom count, lot size, or condition on file.
Unequal (non-uniform) assessment. Comparable properties in your area are assessed for less than yours, regardless of market value.
Physical or external problems. Deferred maintenance, functional issues, or an external nuisance depress what a buyer would pay.
Decline in value (Prop 8) · Incorrect base year value · Change in ownership dispute · Calamity reduction
Don’t overlook exemptions
An appeal lowers your value, but exemptions cut your taxable base directly — and both stack. Most owners qualify for a homestead exemption on their primary residence, and many states add relief for owners over 65, veterans, and people with disabilities. Confirm you are enrolled with your California county assessor before filing — it is the fastest saving most people miss.
- Homeowners' Exemption $7,000 assessed value
- Owner-occupied primary residence
- Disabled Veterans' Exemption $100,000–$150,000 assessed value
- Qualifying disabled veterans
- Senior Transfer (Prop 19) Base year value transfer
- Age 55+, primary residence
- Parent-Child Transfer (Prop 19) Limited base year value transfer
- Primary residence transfers to children
Who hears a California appeal
Your appeal is decided by County Assessment Appeals Board — the value itself is set by the County Assessor, which is who you are disagreeing with.
- 1
Assessor informal review
- 2
Assessment Appeals Board hearing
- 3
Superior Court (limited)
Each stage has its own deadline. Missing the first one usually closes the later ones for that tax year.
Key California statutes
The sections a California appeal is argued under. Quote one exactly as written — a paraphrased or renumbered citation is worse than none.
- R&TC §51
- Base Year Value (Prop 13)
- R&TC §68
- Change in Ownership
- R&TC §69.5
- Senior Transfer (Prop 19)
- R&TC §218
- Homeowners' Exemption
- R&TC §531
- Escape Assessments
- R&TC §1603
- Application for Changed Assessment
- R&TC §1604
- Filing Deadline
- R&TC §2611
- Supplemental Assessment
Official California resources
These are state government sites. The form and portal you actually file through are published by your county assessor.
California property tax appeal questions
- When is the deadline to appeal property taxes in California?
- July 2 – November 30 (most counties); September 15 (San Francisco). Verified July 2026. Deadlines vary by county and change from year to year, so always confirm the date printed on your own assessment notice before you file.
- Who decides a property tax appeal in California?
- County Assessment Appeals Board hears it. The full path is: Assessor informal review, then Assessment Appeals Board hearing, then Superior Court (limited).
- What is the assessment ratio in California?
- 100% of base year value. That is the share of value your bill is calculated on, so lowering the assessed value lowers the bill proportionally.
- What grounds can I appeal on in California?
- California recognises these grounds: Decline in value (Prop 8), Incorrect base year value, Change in ownership dispute, Calamity reduction. Overvaluation is the most common — you show comparable sales that closed below your assessed value.
- What property tax exemptions does California offer?
- Homeowners' Exemption — $7,000 assessed value, for owner-occupied primary residence; Disabled Veterans' Exemption — $100,000–$150,000 assessed value, for qualifying disabled veterans; Senior Transfer (Prop 19) — Base year value transfer, for age 55+, primary residence; Parent-Child Transfer (Prop 19) — Limited base year value transfer, for primary residence transfers to children. Exemptions reduce your taxable base directly and stack with an appeal, so check both.
- What is the average property tax rate in California?
- About 0.7% of market value per year statewide. Your own rate depends on your county and its taxing districts, so treat this as a benchmark rather than your bill.
California Tax Estimator
$0 / yr
Based on 100% ratio & avg. millage. Estimate only.
Generate your California appeal packet
Check your property for $4.99 (credited), then get the full comparable-sales packet and AI appeal letter for a flat $29 — $19 at launch.