General Contact Number: (530) 621-5567




State law requires the Assessor's Office to reappraise property upon change of ownership or completion of new construction. The Assessor's Office must issue a supplemental assessment that reflects the difference between the prior and new assessed values. The tax liability is calculated by the Auditor and is pro-rated based on the number of full months remaining in the fiscal year, ending June 30. This is in addition to the regular tax bill. A Notice of Supplemental Assessment is mailed to the property owner before the Supplemental Tax bill is issued.

For example, if you purchased property in September, worth a market value of $250,000, and the previous assessed value of that property was $200,000, you would receive a supplemental assessment on the difference ($50,000). Generally, the supplemental assessment ($50,000) would be multiplied by the appropriate tax rate (say 1.08%) and pro-rated for the full months remaining in the fiscal year (9/12 months = .75). This supplemental tax liability ($50,000 x 1.08% x .75 = $405.00, using the criteria of the example) is in addition to the annual tax bill.

Supplemental bills are mailed to you rather than your lender. Please contact your lender to determine if they will pay the supplemental bill on your behalf from an impound account that may be established for the benefit of your property

All exemptions (Homeowner's, etc.) shall be allowed on the supplemental assessments unless they have already been granted on the regular assessment. A claim for exemption must be filed with the Assessor's Office on or before the 30th calendar day following the date of mailing of the Notice of Supplemental Assessment.