County filing guide
How to appeal your property tax in San Luis Obispo County
Regular decline-in-value appeals. Supplemental and escape assessments have different deadlines.
Filing options
Filing instructions
Informal review
The annual assessment-review instructions give a July 2, 2026–December 31, 2026 filing period. The current decline-in-value form says applications received after December 31, 2026 are considered for the next tax year. The review is free.
Open Assessment Review Requests. Download Decline in Value Form and read Assessment Review Request Instructions.
Open the informal review information. Complete both sides of the decline-in-value form. Supply your parcel and assessment numbers, contact and purchase details, current taxable value and your opinion of market value as of January 1 of the year under review.
Add comparable sales and supporting information. The form has space for three sales and permits additional sheets. Follow its restriction on sales after March 31 of the year being reviewed; include the requested income information if the property is multi-unit or commercial.
Sign and date the form, then mail it with your supporting material to County Assessor, 1055 Monterey Street, Suite D360, San Luis Obispo, CA 93408 so it is received by December 31, 2026 for the current year. Keep a copy. Signing allows an inspection, including interiors; an appraiser will arrange an appointment if needed.
Review the Assessor’s findings. The informal request does not extend the formal appeal deadline, and property taxes remain due on time. For questions, call 805-781-5643.
The formal appeal window for 2026-27 has closed. The deadline was September 15, 2026. These instructions remain available as a reference.
Formal appeal
The regular annual filing window is July 2, 2026–September 15, 2026. These paper-process instructions remain a reference after that window closes; supplemental and other assessments have their own deadlines. An informal review does not extend the formal appeal deadline.
Open the Assessment Appeals page. Under Complete the Assessment Appeal Application, download Assessment Appeals Application form.
Download the assessment appeal application. Fill out BOE-305-AH with the applicant, property and assessed-value information. Enter your proposed value and complete the remaining applicable questions. For a regular annual market-value appeal, select Regular Assessment and Decline in Value. Keep hearing evidence for the hearing rather than attaching it to this application.
Print the application, sign in blue ink and date it. Keep a copy. Downloading or filling the PDF online does not file an appeal.
During the applicable filing window, mail the original signed application with the $66 nonrefundable fee per application/parcel to Assessment Appeals Board Clerk, 1055 Monterey Street, D430, San Luis Obispo, CA 93408. The form names County of San Luis Obispo as payee. Check with the Clerk at 805-781-5011 if payment instructions are unclear.
Watch for the hearing notice and confirm attendance at least 21 days before the hearing, using the method in that notice. Prepare your evidence and follow the notice’s instructions. Continue paying your property taxes on time.
After you file
Informal review
Keep your request confirmation and any correspondence from the Assessor. Check the formal appeal deadline above when considering a separate appeal.
Formal appeal
Keep a copy of your application and filing confirmation. Watch for notices from the Clerk of the Board and follow the county’s instructions for any hearing.
Open my appeal plans →Contacts & sources
Clerk of the Board
Runs the formal appeal
805-781-5011 · appeals page ↗
1055 Monterey Street, D430, San Luis Obispo, CA 93408
This guide covers the regular decline-in-value appeal; supplemental or escape assessment notices follow different deadlines. Every date and fee here was checked against official sources, listed below with the date checked. If the county's page ever differs from this guide, follow the county's page.
Sources
Informal sources
- Assessment Review Requests — actual download menu, inspected in Chrome and captured October 8, 2026.
- Decline in Value Form — two-page SLO-RP-41 revision 07/27/26; required information, three sale rows, additional sheets, income-property evidence, signature, inspection consent and December 31 receipt cutoff. PDF text inspected October 8, 2026.
- Assessment Review Request Instructions — July 2–December 31 annual review period, submission to the Assessor at Suite D360, review/appeal distinction and unchanged appeal deadline. Document revision 07-22-20.
- Assessment Reviews pamphlet — no review charge and notification of results; document revision 08-17-21.
- Scope: public menu and forms verified; later preparation, mailing and review are document-backed. The form lists an email address, but no explicit instruction accepting email filing was established. The guide uses the instructions’ paper submission route. No request, account, signature or payment was submitted. Screenshot annotation and target readability checked locally; screenshot embedding, placement and rendered Notion images were verified on 2026-10-14.
Informal review
- https://www.slocounty.ca.gov/departments/assessor/forms-documents/assessment-and-real-property-valuation/assessment-review-requests/assessment-review-request-instructions · “For the annual assessment roll, the filing period is between July 2nd and December 31st.” (checked July 11, 2026)
- https://www.slocounty.ca.gov/departments/assessor/forms-documents/assessor-s-office-pamphlets/assessment-reviews · “There is no charge for filing an Assessment Review Request.” (checked October 14, 2026)
Formal sources
- Assessment Appeals — public procedure, paper filing in person or by mail, July 2–September 15 regular filing period, nonrefundable fees and hearing attendance confirmation at least 21 days in advance. Inspected in Chrome October 8, 2026.
- Current application — BOE-305-AH revision 12 (05-24), county fee effective July 2, 2026; $66, named payee, Suite D430 mailing address, blue-ink original signature and no hearing-evidence attachments. PDF text inspected October 8, 2026.
- FY 2026–27 Executive Office fee schedule — independently confirms $66 per application.
- Verification scope: public entry and current linked form verified; subsequent filing and hearing steps are document-backed. The main appeals page still links the FY 2025–26 fee schedule, and a search result retained an older $65.75 form amount. Direct inspection of the current form and FY 2026–27 schedule resolves the current fee to $66. No online appeal submission portal was found on the official filing page. No authenticated screens were invented and no application/payment was submitted. Filing copy count, permitted payment instruments and fee-waiver availability were not established. The reference instructions must be checked against the next year’s filing notice and fees before a future filing.
Formal appeal window
- https://www.boe.ca.gov/proptaxes/pdf/lta26023.pdf · “The regular appeals filing period in each county will begin on July 2, 2026, and will end on September 15, 2026, for those counties where the Assessor mails assessment notices to all taxpayers with property on the secured roll by August 1, 2026. For counties where assessment notices are not mailed by August 1, 2026, the filing period is extended to November 30, 2026.” (checked July 10, 2026)
Filing fee
- https://www.slocounty.ca.gov/departments/administrative-office/forms-documents/county-fees-and-fee-schedules/county-schedule-b-fees-(effective-7-1-2026-to-6-30-2027)/104-executive-office_schedule-b_fy-2026_27 · “Filing an Assessment Appeals Application $66.00 per application” (checked July 11, 2026)
Filing address
- https://www.slocounty.ca.gov/departments/administrative-office/clerk-of-the-board/clerk-of-the-board-services/assessment-appeals · “1055 Monterey Street D430 San Luis Obispo, CA 93408” (checked July 11, 2026)
Filing channels
- https://www.slocounty.ca.gov/departments/administrative-office/clerk-of-the-board/clerk-of-the-board-services/assessment-appeals · “Applications may be filed in person at the Executive Office or by mail, along with the appropriate fees.” (checked October 14, 2026)
Common questions about appealing in San Luis Obispo County
When is the deadline to appeal in San Luis Obispo County?
The 2026-27 filing period for a formal appeal in San Luis Obispo County ran from July 2 to September 15, 2026, so it has closed for this tax year.
The Assessor takes informal review requests from July 2 to December 31, 2026.
What does it cost to file an appeal in San Luis Obispo County?
The county filing fee for a formal appeal is $66.
There is no fee for the Assessor's informal review.
Informal review or formal appeal: which one first?
San Luis Obispo County offers both: an informal review with the Assessor, and a formal appeal filed with the Clerk of the Board (due September 15, 2026).
The state's own guidance says to talk to the Assessor's office first: if their staff finds an error, they can lower the roll directly and you may never need to file. Missing an informal review costs you nothing; missing the formal deadline costs you the year.
Which form do I file, and where?
The formal appeal uses the state's application form, BOE-305-AH ↗.
San Luis Obispo County accepts the formal appeal by mail or in person.
Mail it to the Clerk of the Board at 1055 Monterey Street, D430, San Luis Obispo, CA 93408.
Check the Clerk of the Board's appeals page ↗ or call 805-781-5011 before you file.
How long does an appeal take?
You get written notice at least 45 days ahead, hearings are open to the public (you can watch one first), and boards are expected to decide within two years of filing. You can still settle at any point before your date.
Do homeowners actually get their assessments lowered?
More than 150,000 homes across California had temporarily reduced assessments in tax year 2025-26.