Commercial & Business Property
California Commercial Property Tax Appeals
Office, retail, industrial, multifamily, and special-purpose buildings in California are frequently over-assessed. Here's how commercial assessments work, the deadline to challenge yours, and what it takes to win.
How commercial is assessed
California assesses at the Proposition 13 base-year value (set at purchase or new construction) plus up to 2%/year. Commercial is NOT split-rolled — Prop 15 failed in 2020 — so business property stays under the same Prop 13 framework as homes.
No split roll: commercial and residential share the Prop 13 base-year system.
Burden of proof
For commercial property the applicant bears the burden of proof (unlike an owner-occupied single-family home, where the assessor carries it). The case rests entirely on the evidence you present.
Key to a California commercial appeal: Proposition 8 decline-in-value
When a commercial property's current market value falls below its factored Prop 13 base — common after a market correction, or when a specialized buildout (e.g. a cannabis conversion) was assessed at cost — the county must temporarily lower the assessment, cutting the bill and triggering a refund. File the formal BOE-305-AH with the Clerk of the Board during the July 2–Nov 30 window.
California Filing Deadline & Where to File
File With
County Assessment Appeals Board
Deadline
September 15 (regular) or November 30 (some counties extend to Nov 30)
Window Opens
July 2 (regular roll) or within 60 days of supplemental notice
Typical Duration
6–18 months (backlogs common in large counties)
Prop 13 limits increases to 2%/year from purchase price. Appeals focus on decline in value below Prop 13 base. LA County has 12+ month backlogs.
⚠️ Deadlines vary by county/municipality in California. Confirm the exact date for your property's jurisdiction before filing.
How commercial value is proven
Income-producing commercial property is usually valued by capitalizing net operating income (NOI ÷ market cap rate). The strongest appeals come with a clean rent roll, a trailing-12-month operating statement, current vacancy, and market cap-rate support. Where the property is owner-occupied or special-purpose, the cost and sales-comparison approaches carry more weight.
Evidence that wins a commercial appeal
- Current rent roll and a trailing-12-month operating statement
- Actual vacancy and collection loss (vs the assessor's stabilized assumption)
- Market capitalization rate support for the property type and submarket
- Recent arm's-length sales of comparable commercial buildings
- Evidence of physical, functional, or economic obsolescence
- Any change in use, tenancy, or condition since the assessment date
How to appeal a commercial assessment in California
- 1Pull the assessment — confirm the assessed value, the assessment ratio/class, and how the assessor derived it (income, cost, or sales).
- 2Build the valuation — capitalize actual net operating income and gather comparable sales to establish market value as of the assessment date.
- 3File before the deadline — submit to County Assessment Appeals Board by September 15 (regular) or November 30 (some counties extend to Nov 30), with the authorization signed by someone able to bind the owning entity.
- 4Present at the hearing — commercial hearings are evidence-driven; a clean income approach and credible comps carry the day.
Think your California commercial property is over-assessed?
We pull the assessment, build the income-approach case, and file the appeal. Fee: 20% of first-year savings — only if we win. Nothing upfront, and the reduction can hold for years.
Related resources
Assessment ratios, class rates, and deadlines in California are set by statute and can change year to year, and often vary by county or municipality. Verify current figures and dates with your county assessor or clerk of the board before filing. This page is general information, not legal or tax advice. TaxedFairly is a product of WebLab LLC.