Assessor
Find property assessments, parcel information and property tax exemptions.
Source checked October 12, 2026[1]sonomacounty.gov
Opens this office’s own website. CountyWiki does not process applications, take payments or provide personal records.
Contact details & office locations ↓Online services & information
These links were found on official source pages. Each service is handled by the office.
County instructions for Assessor parcel information, value notices and maps, with separate third-party and ActiveMap options. Name searches are unavailable; ActiveMap’s listed zoning and land-use details apply to unincorporated areas.
Before you start
- Availability · Online ownership privacy
- Search by parcel number or address. Owner-name searches and owner names in results are unavailable. [10]
- Availability · Value-change notices — delivery
- The county says assessed-value-change and Prop 8 notices are available online and are no longer mailed unless specifically requested. [11]
- Availability · ActiveMap zoning and land-use coverage
- The listed zoning and land-use information is for unincorporated Sonoma County. Confirm city information with the appropriate city. [12]
Official assessor maps and property information. Read the office’s current requirements before continuing.
County-linked Assessor query for parcel information, value notices and maps.
County-linked ActiveMap viewer collection. The listed zoning and land-use coverage is limited to unincorporated areas.
Fees
Fees are quoted only when a source document supports the amount and conditions.
Check the official website for its current fee schedule. No fee should be assumed to be free.
Forms & documents
Official forms and document pages for this office’s services.
Sources & last checked4 source pages · 12 citations
Sources were checked by an AI-assisted research process. A checked website does not mean every service or fee on it has been reviewed.
- [1] Sonoma County — departments directory (opens in a new tab)
Sonoma County · Department directory: Assessor
Source reviewed October 12, 2026View supporting excerpt
Assessor's Office
- [2] Sonoma County — assessor (opens in a new tab)
Sonoma County · Service link: Parcel Maps
Source reviewed October 12, 2026View supporting excerpt
Parcel Maps
- [3] Sonoma County — assessor (opens in a new tab)
Sonoma County · Forms/document link: Assessor Forms
Source reviewed October 12, 2026View supporting excerpt
Assessor Forms
- [4] Sonoma County Assessor — About and contacts (opens in a new tab)
Sonoma County Assessor · Contact us by Phone — Main Office
Source reviewed October 14, 2026View supporting excerpt
(707) 565-1888
- [5] Sonoma County Assessor — About and contacts (opens in a new tab)
Sonoma County Assessor · Assessor’s Office — Address
Source reviewed October 14, 2026View supporting excerpt
585 Fiscal Drive Room 104F Santa Rosa, CA 95403
- [6] Sonoma County Assessor — About and contacts (opens in a new tab)
Sonoma County Assessor · Assessor — Business Hours and transaction cutoff
Source reviewed October 14, 2026View supporting excerpt
Monday – Tuesday 8:00 AM – 5:00 PM Wednesday 8:00 AM – 4:00 PM Thursday – Friday 8:00 AM – 5:00 PM Note: No fee transactions or document processing within 30 minutes of closing
- [7] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — Parcel information — Assessor query, maps and notices
Source reviewed October 15, 2026View supporting excerpt
Search results include Assessor Parcel Number lookup, basic parcel information, value notices and parcel maps
- [8] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — Open the Assessor parcel-information query
Source reviewed October 15, 2026View supporting excerpt
Search Assessor's Parcel Information Now
- [9] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — Open ActiveMap GIS resources
Source reviewed October 15, 2026View supporting excerpt
Search an interactive map with a large choice of geographic, detailed and general map data for the unincorporated areas of Sonoma County.
- [10] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — Online ownership privacy
Source reviewed October 15, 2026View supporting excerpt
Searches by name are not available and the search results will not include owner name.
- [11] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — Value-change notices — delivery
Source reviewed October 15, 2026View supporting excerpt
the Assessed Value Change Notices and Prop 8 Notices will no longer be mailed through the U.S. Postal Services unless specifically requested.
- [12] Sonoma — property query (opens in a new tab)
Sonoma County official service / referred provider · County property lookup — ActiveMap zoning and land-use coverage
Source reviewed October 15, 2026View supporting excerpt
Zoning and Land Use codes, Groundwater Availability, Supervisorial District, Williamson Act Land Contract, etc. (unincorporated areas only)