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Real Property

Properties Affected Flood or Fires

Has your property suffered or been destroyed by the Kincade Fire, February Floods, or the 2017 Complex Fires? 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.


How to Find Out Who Owns a Property

Online Information

Look up basic property information online. Available 24/7, you can search by street address or by parcel number for information such as land value, improvement value, personal property value, exemption value, lot size, and net values. The owner's name is not available online.

Assessed Owner Information / Remote Services

Our office can confirm the current assessed owner of record for a property (maximum 3 requests per email/phone call)

Information Available at Our Office

If you know the street address, parcel number or owners name, you can use a public kiosk to access the Assessor's computerized property data system during normal business hours. Printing is available for a small fee. 

Property Information for Sale

In addition to basic Assessment Roll information such as owner names, property addresses, and assessed property values, the County Assessor can provide a variety of data about Sonoma County properties to interested parties.

Parcel maps, various detailed reports, and other kinds of information are available for purchase.

Ways to Save on Property Taxes

Exemptions, Exclusion and Temporary Decline in Market Value Review may offer property tax savings for your property if certain conditions are met.

Some of the more common options include:



Temporary Property Value Decline

Property Transfers

When a there is a change in the manner that title is being held, the Assessor receives a copy of the recorded deed or other official document and determines if an appraisal is required under State Law.

An ownership transfer may trigger reappraisal of your property resulting in a change in your property taxes.  If reappraisal is required, an appraisal is made to determine the new assessed value.  You will be notified of the new assessment and the right to appeal. 

Supplemental Assessments

The County Assessor must appraise property at its market value on the date of a change in ownership or when new construction is completed. The difference between the property's newly determined value after one of these events and the value which was previously enrolled on the Annual Assessment Roll results in a supplemental assessment. Contact our office for more information.

Home Reappraisal Events

Remodeling Your Home

Your entire home will not be reappraised if you add on another room. Only the market value of the new addition will be added to your assessed value. The new construction is assessed at the market value it adds to the property, not the cost of the contractor or materials.

Purchasing Property

Real property is valued at its current market value at the time it changes ownership. In a majority of cases, the sales price equals market value, but not always. The unpaid balance of any improvement bonds on the property may be included in the market value.

Adding Someone to Your Title

An Ownership transfer may trigger reappraisal of your property resulting in a change in your property taxes. For your protection we recommend that you contact an attorney as the law prohibits Sonoma County employees from answering questions of a legal nature; therefore we cannot advise you how to hold title or which type of document to record and we cannot assist you with the document.


Assessor Maps

  • The Assessor's maps are developed and maintained for property tax administration purposes only and do not establish “legal parcels”

Certificate of Compliance

  • The Assessor does not split parcels with a Certificate of Compliance. A Planning Department Certificate of Compliance signifies that the Planning Department would recognize the affected parcels as being "legal" if they were to be split or sold, but this certificate doesn't pertain to changes in value or ownership.

Property Tax Information

The Assessor's Office does not create or mail out tax bills or collect tax payments. The Sonoma County Treasurer-Tax Collector creates and mails property tax bills and collects Secured Property Taxes, Supplemental Property Taxes and Unsecured Property Taxes.

Search property tax record information or pay your property taxes online by visiting the Sonoma County Treasurer-Tax Collector.

Certified Information Available to Homeowners

Information is available to give to your mortgage company so impound accounts will be based on a new purchase price.

Generally, the Sonoma County Tax Collector may be able to help you with this request. Contact the Tax Collector's Office for help with tax bills and assistance for impound information. Contact them at (707) 565-2281 or at