Request Informal Review

Value Review

If you believe that the market value on January 1 is less than the Assessor's assessed value of your property for the same date, you may use the Informal Assessment Review form located below to request an informal review of your assessed value. There is no fee to request an informal assessment review. For additional information on Decline in Value and Proposition 8, refer to the sections below or contact the Assessor's Office at 530-265-1232. 

Download the Request For Informal Assessment Review 2024-2025 (PDF) Or complete an E-File Request for Informal Assessment Review 2024-2025 Form.

Proposition 13 - Base Year Value

Proposition 13, passed in 1978, establishes the base year value concept for property tax assessments. Under Proposition 13, assessments for the year 1975 to 1976 serve as the original base year values. Thereafter, a new base year value is established whenever a property is purchased, newly constructed or changes ownership. The base year value may increase a maximum of 2% per year.

Proposition 8 - Temporary Decline in Value

Proposition 8, passed in November 1978, amended Proposition 13 to recognize declines in value for property tax purposes. Prop 8 decline in market value assessments are temporary reductions that recognize the fact that the market value of a property as of the January 1 lien date has fallen below its Proposition 13 factored value. The Revenue and Taxation Code authorizes the Assessor to annually enroll either the property’s Proposition 13 factored base year value or its market value as of January 1st, whichever is less.

Once a Proposition 8 reduced value has been enrolled, that property’s value must be reviewed each year as of the January 1st lien date, to determine whether its market value continues to be less than its Proposition 13 factored value. Proposition 8 values can change from year to year as the market fluctuates. When the market value of the property increases above its Proposition 13 factored value, the Assessor will once again enroll its Proposition 13 factored value. In no case may a value higher than a property’s Proposition 13 factored value be enrolled.

Properties enrolled under Proposition 8 provisions are not subject to the 2% annual increase limitation that applies to those enrolled under Proposition 13 provisions.


A property owner provides the Assessor with facts or evidence that he / she feels justify a reduction in value and requests a review of the property’s value, or the Assessor may initiate the review if the reduction is discovered independently.

Appraisal staff reviews the property owner’s comparable sales and other market data, estimates the property’s market value as of January 1st and then compares this market value to the property’s current Prop 13 factored base year value.

If the January 1 market value is below factored Prop 13 value, then:

  • Assessed value is lowered to market value for next fiscal year
  • Owner is notified of reduced value
  • New tax bill is based on lower value for next fiscal year
  • The following year, Assessor repeats process and enrolls the January 1 market value at that time or Proposition 13 factored value, whichever is lower

If January 1 market value is higher than factored Prop 13 value, then:

  • No change in assessed value is made, and
  • If owner still feels value should be reduced, then owner may file a formal assessment appeal with the Assessment Appeals Board, from July 2nd through November 30th each year.

Formal Appeal - Assessment Appeals Board (AAB) 

For more information visit the Assessment Appeals Board (AAB) web page and contact Clerk of the Board at  530-265-1480

Assessment Appeals Board hears evidence from owner and Assessor; the Board then determines proper assessed value