Assessment Appeals Board — Clerk of the Board
Assessment appeals board function; provider and jurisdiction must be verified.
Source checked October 15, 2026[4]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.
Sonoma County formal appeal application and hearing resources. An appeal addresses the specific assessment and enrolled year; another year may require another application.
Before you start
- Information & documents · Specific assessment and enrolled year
- File for each disputed assessment and enrolled year. An existing appeal does not challenge other assessments or a later year. [7]
- Deadlines · 2026 regular assessment appeals only
- For Sonoma County’s 2026 regular assessment appeal, file July 2 through November 30, 2026. Other appeal types have separate, notice-based deadlines. [1]
- Information & documents · County-specific formal appeal application
- Use the BOE-305-AH application provided by the county where the property is located; a generic sample is not a valid filing. [2]
- Payments · Taxes while an appeal is pending
- Pay property taxes on time while an appeal is pending to avoid penalties and interest. Filing an appeal does not suspend tax payments. [3]
County application instructions and Assessment Appeals Board contact.
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 · 11 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] 2026 county assessment-appeal filing periods (opens in a new tab)
California State Board of Equalization · BOE LTA2026/023 — page2, 2026 county filing deadline table
Source reviewed October 15, 2026View supporting excerpt
County Assessment Appeals Filing Periods for 2026 The clerks of county assessment appeals boards and county boards of equalization have certified the assessment appeals filing period for their counties pursuant to the requirements of Revenue and Taxation Code section 1603. The regular appeals filing period in each county will begin on July 2, 2026, and will end either on September 15, 2026, or November 30, 2026, depending on whether the County Assessor has elected to mail assessment notices to all taxpayers with property on the secured roll by August 1, 2026. The following table shows the filing deadline for each county: FILING FILING COUNTY COUNTY DEADLINE DEADLINE Alameda September 15 Orange November 30 Alpine September 15 Placer September 15 Amador November 30 Plumas November 30 Butte November 30 Riverside November 30 Calaveras November 30 Sacramento November 30 Colusa November 30 San Benito November 30 Contra Costa November 30 San Bernardino November 30 Del Norte November 30 San Diego November 30 El Dorado November 30 San Francisco September 15 Fresno November 30 San Joaquin November 30 Glenn November 30 San Luis Obispo September 15 Humboldt November 30 San Mateo November 30 Imperial November 30 Santa Barbara November 30 Inyo September 15 Santa Clara September 15 Kern November 30 Santa Cruz November 30 Kings September 15 Shasta November 30 Lake November 30 Sierra September 15 Lassen November 30 Siskiyou November 30 Los Angeles November 30 Solano November 30 Madera November 30 Sonoma November 30 Marin November 30 Stanislaus November 30 Mariposa November 30 Sutter November 30 Mendocino November 30 Tehama November 30 Merced November 30 Trinity November 30 Modoc November 30 Tulare November 30 Mono September 15 Tuolumne November 30 Monterey November 30 Ventura September 15 Napa November 30 Yolo November 30 Nevada November 30 Yuba November 30
- [2] Assessment appeal FAQ (opens in a new tab)
California State Board of Equalization · BOE assessment appeals FAQ
Source reviewed October 15, 2026View supporting excerpt
You must file an Assessment Appeal Application, form BOE-305-AH, obtained from the clerk of the board of the county where your property is located. Some counties have this form available on the website of either the clerk of the board or the county assessor, or both. You must use the county application for the appeal to be considered a valid filing.
- [3] Assessment appeal FAQ (opens in a new tab)
California State Board of Equalization · BOE assessment appeals FAQ
Source reviewed October 15, 2026View supporting excerpt
Yes. You are required to pay your property taxes timely despite any appeal you have pending. Failure to do so will result in financial penalties and interest charges regardless of the outcome of your appeal. If you are granted a reduction, you will receive a refund and interest.
- [4] Sonoma — assessment appeals information (opens in a new tab)
Sonoma County · Assessment appeals — 06097
Source reviewed October 15, 2026View supporting excerpt
A valid and timely Assessment Appeal Application will be scheduled for a hearing before the Assessment Appeals Board.
- [5] Sonoma — assessment appeals information (opens in a new tab)
Sonoma County · Assessment appeals — Assessment appeal — application, annual scope and hearing resources
Source reviewed October 15, 2026View supporting excerpt
A valid and timely Assessment Appeal Application will be scheduled for a hearing before the Assessment Appeals Board.
- [6] Sonoma County — assessment appeal filing (opens in a new tab)
Sonoma County · Assessment appeals — Obtain and complete the county appeal application
Source reviewed October 15, 2026View supporting excerpt
Download the Assessment Appeal Application and Instructions or request a copy from the Assessment Appeals Board:
- [7] Sonoma — assessment appeals information (opens in a new tab)
Sonoma County · Assessment appeals — Specific assessment and enrolled year
Source reviewed October 15, 2026View supporting excerpt
You must file an application for each assessment and each year's enrolled assessed value that you disagree with. Each application deals with that specific assessment, and will not serve to challenge other assessments.
- [8] Sonoma County — assessment appeal filing (opens in a new tab)
Sonoma County · Assessment appeals — Assessment Appeals Board — applications
Source reviewed October 15, 2026View supporting excerpt
Phone: (707) 565-2241
- [9] Sonoma County — assessment appeal filing (opens in a new tab)
Sonoma County · Assessment appeals — Assessment Appeals Board — applications
Source reviewed October 15, 2026View supporting excerpt
AssessmentAppeals@sonomacounty.gov
- [10] Sonoma County — assessment appeal filing (opens in a new tab)
Sonoma County · Assessment appeals — Assessment Appeals Board — applications
Source reviewed October 15, 2026View supporting excerpt
575 Administration Drive, Suite 100-A Santa Rosa, California 95403
- [11] Sonoma County — assessment appeal filing (opens in a new tab)
Sonoma County · Assessment appeals — County assessment appeal application and instructions
Source reviewed October 15, 2026View supporting excerpt
Assessment Appeal Application and Instructions