• Firefighters puting out fire -

    Disaster Relief

  • Operating Your Business

    Learn about Business Property Statements and who must file them

  • Homes in a Neighborhood

    Property value, ownership records and property information

  • Property Information

    Farms, vineyards and ranches must file an annual Agricultural Business Property Statement

  • Russian River Valley

    Williamson Act

Welcome to the Assessor's Office

  • Published on October 30, 2017

    On October 15, 2017, George Adair of Bay Equity Home Loans spoke with William Rousseau, Sonoma County Clerk-Recorder-Assessor on KSRO radio. In the aftermath of the fires, Bill answers many of the questions that are on the minds of property owners

  • Published on October 16, 2017

    Please know that the Sonoma County Clerk-Recorder-Assessor and Registrar of Voters office will do everything we can to help you during this difficult time. We can help replace birth, death and marriage certificates, deeds, and other important recorded documents. Our office is also working diligently to reassess Sonoma  County homes damaged or destroyed by the fires, and assisting residents with disaster relief filings to ease their property tax burden. 

  • More News

California's property tax laws allow the Assessor to adjust assessed values due to a major calamity such as fire, earthquake, or flooding which damages or destroys your real or personal property.  

More about Disaster Relief

Temporary reductions to your property's taxable value on the Assessment Roll can be initiated by either you or the Assessor.

More about Temporary Decline in Market Value and how to apply

Machinery, equipment, tools, furniture, fixtures, and leasehold improvements held or used in connection with a trade or business are taxable. In addition, most boats, aircraft and mobile homes are also taxable. Supplies on hand, demonstration equipment, and construction in-progress are also assessable. 

More about Business Property taxes and filing

There are a variety of options available for lowering your property taxes. Each of these exemptions, exclusions or provisions has specific qualifications.

More about Property Tax Savings


William F. Rousseau

County Clerk-Recorder-Assessor-Registrar of Voters

Business Hours
Monday – Tuesday
8:00 AM – 5:00 PM
8:00 AM – 4:00 PM
Thursday – Friday
8:00 AM – 5:00 PM

Note: Document processing and fee transactions end 30 minutes prior to closing


Assessor's Office

585 Fiscal Drive
Room 104F
Santa Rosa, CA 95403
38.4659106, -122.7251807

Active Scams

Read About Current Scams

Scam Alert!

Active scams for services that are offered at our office for low or no cost!

Property Value

Search Parcel Information

Sonoma County Property Value

Search current maps, parcel information, property values, change notices and more

Electronic Filing

Deadline to File Business Property Statements Passed

eFile Your Property Statement

The deadline was 5/9/2017. We will mail 2018 Notice to File letters February 2018

Online Mapping

ActiveMap Viewer Collection
Access location-based information pertaining to a specific subject and/or area within unincorporated Sonoma County.

Change of Address and Authorization Forms

Download Forms

Assessment Appeals

About Assessment Appeals

Office of the Clerk of the Assessment Appeals Board

Assessment Appeals Calculator

The Assessment Appeals Board is an independent agency under the authority of the Sonoma County Board of Supervisors

Important Notice

Important AnnouncementThe staff of the Clerk-Recorder-Assessor's Office are forbidden by California legal codes to practice law or provide legal advice; this prohibition includes giving advice about what forms you might need or how you should fill them out.