Assessor Information

Lake County Assessor

The County Assessor is responsible for the preparation of the local secured and unsecured assessment rolls which constitute the major portion of the ad valorem tax base for local government. (“Ad valorem” means taxes are based on the assessed value of the property.) The responsibilities included in preparing these rolls are:

Discover and inventory all tangible property within the county.
Determine the taxability of all tangible property within the county.
Value all taxable property as specified under Article XIII of the California Constitution.


Mendocino County Assessor

This Division maintains the county’s record of property owners. It must discover, locate, map and value all taxable property within the county and annually prepare the assessment roll. The roll contains the values of all taxable land within the county, the values of structures, taxable personal and business property, agricultural and timber property and the names and addresses of the owners. This includes the review and application of appropriate exemptions. This Division must perform mandatory audits of businesses whose property statements have exceeded $400,000 for the last four years. This Division represents the County at local assessment appeal hearings.


Napa County Assessor

The Assessor Division has the authority to adjust property taxes due to a calamity. Please read a message from the Napa County Assessor here to see about filing a calamity which can be filed at the Napa Local Assistance Center at 301 1st Street in Napa.

The Assessor Division is working on creating a new public office. In the mean time questions about ownership of real property can be directed to 259-8601 and questions about Homeowners Exemptions can be directed to 259-8752.


Sonoma County Assessor

The Assessor’s Office is a division of the Clerk-Recorder-Assessor and is responsible for providing accurate and timely property assessments and for determining eligibility for various property tax exemptions and exclusions.

There are approximately 183,000 parcels of land in Sonoma County and the Assessor’s Office is responsible for determining the assessed value of each parcel for property tax purposes in accordance with California’s property tax laws.