• 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

  • Firefighters puting out fire -

    Disaster Relief

  • Russian River Valley

    Williamson Act

Welcome to the Assessor's Office

Business Property Hours Changing

Important Information 58x26Temporary Reduction in Business Property Phone and In-Person Service Hours

As of April 8th, the Business Property office is closed between 12:00 PM and 1:00 PM.

Properties Affected by the Floods

Has your property suffered or been destroyed by the Sonoma County Floods? The Assessor's Office is here to help you during this difficult time.

It is important to know that you have 12 months from the event date to file the Calamity Damage Reassessment form, so you can wait until your insurance agency has inspected your property before filling out the form.

If you will be living somewhere else for an extended period of time, please fill out a Change of Mailing Address Form right away so that we can contact you if needed.


Latest 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


Deva Marie Proto

County Clerk-Recorder-Assessor-Registrar of Voters

Office 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

Business Property Hours

Monday - Tuesday
8:00 AM – 12:00 PM
1:00 PM – 5:00 PM
8:00 AM – 12:00 PM
1:00 PM – 4:00 PM
Thursday - Friday
8:00 AM – 12:00 PM
1:00 PM – 5:00 PM

Assessor's Office

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

Electronic Filing

Deadline to File Business Property Statements Has Passed

eFile Your Property Statement

The deadline was 5/7/2019. We will mail the 2020 Notice to File letters February 2020.

Flood Damaged Property

Search Parcel Numbers

Flood Update

Start by looking up the Assessor's Parcel Number (APN) with this tool using the full, or partial address

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

Online Mapping

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

Fire Rebuild Operations

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 Information 75x40The 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.