Learn about tax savings: decline-in-value

Tax savings: Decline-in-Value

Your property taxes are based on its assessed value. If your property's market value goes down, the Office of the Assessor-Recorder can lower your property assessment. This occurs when the market's value of your property falls below your property's current assessed value.

• Watch a video about decline-in-value
• Read our fact sheet about valuing your property for examples and more information 
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Proposition 8

Reductions in value are also frequently cited as a proposition 8 review. The name comes from the passage of Proposition 8 in 1978.

If your current assessed value (factored base year value) is below market value, the assessor is required to enroll the lesser of your factored base year value (assessed value) or the market value. 

The law allows us to reduce your property taxes by enrolling the fair market value. This is a temporary reduction. Once the value is reduced, we will review your property's value on January 1 each year. We will determine whether its current market value is still less than its adjusted base year value.

When your property's market value increases above its base year value (original asssessed value), we will enroll the base year value. The market may fluctuate from year to year. The important thing is your property taxes won't go higher than the original value they were based on.

How we determine declines in value

Our office makes every effort to review declines-in-value. We reassess property at the lesser of market value or factored base year value each year. Our office may reassess without the need for you to make an informal request or file a formal appeal.

Request a decline-in value

If you believe your assessed value is greater than market value and have information you’d like us to consider, you may request an Informal Review with our office and a certified appraiser will review the data.

Apply for an informal review of the market value of your property. 

You should apply for a decline in value appeal with the Assessment Appeals Board (AAB) if you disagree with the findings of this process.  The market value of the property can change yearly, and property owners may disagree with the assessed value from our office. 

Frequently asked questions

Decline-in-value appeals

Question: Who can file a formal appeal? 

Answer: An assessment appeal can be filed by the property owner or the owner's spouse, parents, or children, or any person directly responsible for payment of the property taxes; this person becomes the Applicant. An application may also be filed by an authorized agent. If an application is filed by an agent - other than a California licensed attorney - an Agent Authorization form, signed by the applicant, is required.

Question: What are the various deadlines for filing an assessment appeal?

Answer: Decline-in-value assessment appeals must be filed between July 2 and September 15th. If September 15th falls on a Saturday or Sunday, applications postmarked on the next business day shall be considered timely. 

• Supplemental assessment appeals must be submitted to the Assessment Appeals Board within 60 days of the date of notice issued by the Assessor. Escape assessment appeals, correction to the roll, or other roll changes must be submitted within 60 days of the date of notice issued by the Assessor. Appeals for a reassessment of property damaged by misfortune or calamity must be submitted within 6 months of the date of notice issued by the Assessor. For more information please visit the Assessment Appeal Board's website.

Question: What if I never received a notice of assessment, do the same deadlines still apply?

Answer: If a notice of assessment was never received, then a tax bill will be used as the first instrument that reflects an assessment adjustment. The application must be accompanied by a penalty of perjury declaration stating that no notice was received.

Question: What tax year am I appealing? 

Answer: The assessed value being appealed will cover the fiscal year from July 1 to June 30 of the following calendar year. The date of value for comparison is the January 1, preceding this tax year (For instance the 2025 tax year is the fiscal year running from 7/1/25 through 6/30/26 and the date of market comparison for any adjustments the fair market value as of 1/1/2025.)

Question: If the assessor or the assessment appeals board agrees to reduce my value, will the new assessment be permanent?

Answer: No. The reduction is temporary and only applies to the tax year being appealed. Any reduction to the assessed value is automatically reviewed annually as of the lien date to determine if market conditions indicate that the assessed value should be maintained, lowered, or increased.

Question: Can I file for an appeal and an informal review?

Answer: Yes. If your property qualifies for an informal review and you are not satisfied with the decision by our office – a Notice of Assessed Value Letter will be mailed to you by the end of July informing you of our value decision – you may file a formal appeal with the Assessment Appeals Board between the dates of July 2 and September 15.

Informal review

Question: Why are tenancy-in-common (TICs) units excluded?

Answer: Unlike residential condominiums and cooperative units, TICs do not have separate parcel numbers. A review of a single TIC unit is more complex. TIC owners can appeal their property assessed values by filing an Application for Changed Assessment with the Assessment Appeals Board beginning July 2 through September 15 of every year.