What are Assessment/Assessor Parcel Maps
The Assessor establishes and maintains a set of maps for every tax parcel in the County for assessment purposes. These maps serve as the basis for assessment of all real property in Sonoma County.
In Sonoma County, there are more than 1,800 assessor’s maps, representing almost 187,500 parcels of land. These maps cover the entire county, including all cities and unincorporated areas.
Assessor maps show the assessor’s parcel numbers for the tax parcel, which may or may not be the same as the legal lot. Legal lot information can be found on official maps of record or recorded deeds which are available at the County Recorder’s Office.
Being based on recorded documents, the assessor parcel maps may not match what is seen or measured in person on the ground or what is seen on various map overlays and/or aerial photographs. Assessor Maps are NOT surveys and should not be used in defining property lines. The Assessor's office mapping staff is always available to answer your questions about how your property is mapped and numbered for assessment purposes.
Accessing an Assessment/Assessor Parcel Map Online
You can view the current Assessor Parcel Maps via the online Assessor Portal. For historical assessors maps, please contact the Mapping Division at 707-565-1888 or email@example.com.
- Find the property by searching by Fee Parcel (APN), Assessment Number or Street Address.
- If entering Street Address, enter the number and street name only. Do not enter the street suffix, such as Drive, Dr, Street, St, etc.
- Click on the property you are interested in viewing
- Select View Maps
Other Map Information
For information on official recorded maps or documents, please contact the Sonoma County Clerk-Recorder. The Recorder’s Office has various types of maps, including records of survey and subdivision maps, as well as recorded deeds and easements. Click here to learn more about recorded maps.
For information on land use and zoning or for starting the process for easements, lot line adjustments, voluntary mergers, parcel maps, or corner records, please contact the Sonoma County or local City planning department.
Frequently Asked Questions
- The first three numbers of the series identify the map book the real property is located in
- The next three digits represent the page number and block within the map book
- The next three digits are used to identify the number assigned to a parcel
- The last three digits are zero
These can be accessed via the online Assessor Portal or in the Assessor’s office.
This information can be found by checking the most current published assessor parcel map or by contacting our office. Contact us at 707-565-1888 or firstname.lastname@example.org.
Parcel number changes become effective in the tax roll year following the tax roll year in which they are completed. For example, a parcel number change completed in July 2022 (during the 2022-2023 tax roll year) will be effective for the 2023-2024 tax roll year and the annual property tax bill that will be mailed in October 2023.
Assessor Parcel map are for assessment purposes ONLY. To identify the physical boundaries of your property, you will need to contact a licensed land surveyor or civil engineer.
A copy of the legal description for your property may be found on the most recent recorded deed. If you do not have a copy of your deed, you can get a copy from the Sonoma County Clerk-Recorder's Office or search their records online.
If you are unable to locate this document, it is recommended you contact a title company.
There are several reasons an assessors parcel may not be the same legal parcel. If you have questions regarding a particular parcel and why it is represented a certain way, you may contact our office here.
Addresses are assigned by Permit Sonoma or local City planning department.
Easements can be created by maps, by deeds, or by agreements between parties. An easement may be referenced in the legal descriptions of a recorded deed. Documents creating easements may be recorded separately from or after the original deed is recorded. Often the easiest way to locate an easement is by obtaining a preliminary title report from a title company. Easement information is not maintained on the assessor’s parcel maps. For public easement information, contact the Planning Department of the jurisdiction where the property is located.
The Mapping Section processes deeds/maps in the date order they are recorded, approximately 6 months in arrears. This means that if a document or map records January 1st of a given year, it will not be acted on for at least 6 months. Processing times may vary due to workload and timing in relation to the annual tax roll preparation processes. New assessor parcels are not created during May and June of each year due to annual tax roll preparation processes. Contact our office at (707) 565-1888 and a member of our Mapping staff will provide an estimate of when the new number(s) will be available.
Not necessarily. The assessor’s maps are developed and maintained for assessment purposes only. You must contact the Planning/Permit Department of your local jurisdiction to confirm the legality of a given parcel.
If you have a disagreement with your neighbor over the placement of a fence, this is a private civil matter that cannot be resolved by the Assessor. We recommend that you contact a licensed professional land surveyor for assistance at the License Look-up for California-Licensed Professional Engineers and Land Surveyors.
Other Mapping Unit Duties
Combination of tax parcels.
- Under certain circumstances, the Assessor’s office may be able to combine assessor’s tax parcels. Please click here for a list of considerations that will be reviewed before this can be approved. This list is not all inclusive but represents the primary criteria.
- If you would like to get more information regarding this process, please contact our office at 707-565-1888 or email@example.com.