California’s property tax system operates unlike any other state—especially when it comes to assessment appeals. Instead of reassessing properties on a set schedule, values typically rise modestly each year—capped by inflation—and are only reset to full market value when certain events occur, like a sale or major construction.
These rules limit how and when values change, but they also create challenges—especially for commercial taxpayers. Knowing when and how to appeal property tax assessments in California can prevent long-term overpayment and impact overall portfolio performance, but many businesses overlook opportunities to challenge assessed values and reduce liability.
Proposition 13 vs. Proposition 8
This system stems from two pivotal measures passed in 1978. While these two measures work together, they affect California property tax assessments in different ways. Understanding the distinction is key to knowing when and how to appeal.
- Prop 13: Caps annual increases in assessed value at 2% or the California Consumer Price Index—whichever is lower—unless a triggering event resets the value to market through a full reassessment.
- Prop 8: Allows taxpayers to request a reduction in assessed value when market value falls below it. These reductions apply on a one-year basis and must be filed annually.
While these rules can offer long-term stability, they also create risk—particularly for commercial properties. Assessed values continue to rise each year, but the system does not automatically account for market decline or sector-specific downturns. Without action from the taxpayer, overassessment can persist for years—especially in underperforming asset classes.
When California Properties Are Reassessed and When You Can Appeal
Prop 13 Reassessments
County assessors do not conduct planned reassessments. Instead, reassessments occur only when specific events take place—typically involving ownership changes or property improvements. When a triggering event occurs, the property is reassessed at full market value, and the 2% cap no longer applies.
What Triggers a New Valuation in California?
These events eliminate the annual cap and trigger a full or partial reassessment to market value.
| Triggering Event | Common Impact |
|---|---|
| Change in Ownership | Full reassessment to current market value |
| New Construction/Renovation | Reassessment of new or improved portion |
| Legal Entity Transfer | Reassessment if controlling interest changes hands |
| Subdivisions or Mergers | Parcel changes may prompt new valuation |
When reassessed, a property is valued at full market value as of the lien date following the event. These step-ups can substantially increase tax liability, particularly in appreciating sectors. California taxpayers should have any reassessed values reviewed by a property tax professional to identify potential assessment appeal opportunities and avoid overpaying.
Prop 8 Appeals
Even without a reassessment, taxpayers in California may still qualify for a one-year reduction under Proposition 8—but only if they proactively file an appeal. Prop 8 applies when a property’s market value falls below its current assessed value—a common occurrence in underperforming sectors.
Sectors often affected include:
- Office (especially downtown and suburban Class B/C)
- Hotels and hospitality
- Retail centers and malls
- Senior living and healthcare facilities
These appeals must be filed proactively every year to be applied—they are not automatic. Annual relief under Prop 8 can significantly reduce overpayment when market values decline.
If your property’s market value has declined, consult a property tax professional experienced in Prop 8 reductions to assess whether an appeal could reduce your liability.
California Assessment Appeal Deadlines
Assessment notices in California are typically mailed in July, with appeal windows beginning July 3. Many California counties do not send annual assessment notices unless there is a change in value. Appeal deadlines vary by county:
| Appeal Deadline | Counties |
|---|---|
| September 15 | Alameda, Alpine, Inyo, Kings, Placer, San Francisco, San Luis Obispo, Santa Clara, Mono, Sierra, Ventura |
| November 30 | Amador, Butte, Calaveras, Colusa, Contra Costa, Del Norte, El Dorado, Fresno, Glenn, Humboldt, Imperial, Kern, Lake, Lassen, Los Angeles, Madera, Marin, Mariposa, Mendocino, Merced, Modoc, Monterey, Napa, Nevada, Orange, Plumas, Riverside, Sacramento, San Benito, San Bernardino, San Diego, San Joaquin, San Mateo, Santa Barbara, Santa Cruz, Shasta, Siskiyou, Solano, Sonoma, Stanislaus, Sutter, Tehama, Trinity, Tulare, Tuolumne, Yolo, Yuba |
Missing the appeal deadline typically forfeits your right to challenge that year’s assessment. You can learn more about California property tax assessment appeals at the California State Board of Equalization’s website.
Why Early Preparation Matters for California Property Tax Appeals
In California, many reassessments occur following planned events—acquisitions, improvements, or entity restructuring. But without early evaluation, the tax impact of those events can be surprising—and opportunities to respond may pass quickly. Likewise, Proposition 8 relief must be re-evaluated annually and supported by market data—a step many taxpayers miss, often leaving potential savings on the table. Early planning for California property tax assessment appeals helps ensure:
- Tax impacts from planned activity are reviewed in advance
- Prop 8 opportunities are accurately identified and documented
- You’re ready to respond when notices arrive or appeal windows open
DMA supports taxpayers across all 58 counties—minimizing risk and maximizing savings through expert property tax appeal strategy.
California Property Tax Expertise
Connect with a DMA specialist to review your California property portfolio and identify opportunities to reduce tax liability. Whether you’re managing long-held assets or responding to ownership or development changes, we help ensure no potential savings are missed.
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| This website content should be used for general informational purposes only, and not as a substitute for consultation with professional tax, legal, or other competent advisors. Before making any decision or taking any action based upon information contained on this website, you should consult with a DMA professional. |