San Luis Obispo County, CA: Property Tax Appeal Instructions (2025-26)

Key facts at a glance

The 60-second primer

Your assessed value for taxes is the lower of (a) your Prop 13 factored base-year value or (b) market value on January 1 (the lien date). If market value is lower, you can seek a temporary Prop 8 reduction for that year.

If you own property in multiple counties, see our county-specific guides for all California counties.

New to property tax appeals? Start with our Appeal 101 guide.

The SLO "Informal" route (Prop 8 review)

Most homeowners should start here. It is free, faster, and often resolves the issue without a hearing. If you're weighing which path to take, check out this comparison between informal and formal appeals.

Step 1: Confirm the value you're trying to beat

Look up your parcel and enrolled value on the county's Property Information Search.

Step 2: Build comps that hug January 1

For SLO's Prop 8 form, sales after March 31 are not considered for this informal review. Aim for 3 to 5 similar sales near January 1 and explain any adjustments. Learn how to find and build comparable sales by matching on bed/bath count, living area, lot, condition, and location.

Step 3: File by December 31

Send the Decline-in-Value (Prop 8) form or Assessment Review Request to the Assessor at Suite D360. If the Assessor hasn't responded by mid-September, proceed to a formal appeal to protect your rights.

Step 4: Keep paying your tax bill

Neither an informal review nor a formal appeal pauses tax due dates.

The SLO "Formal" route (Assessment Appeal)

Use the Assessment Appeals Board (AAB) when the informal track does not get you to fair value.

Step 1: Check your timing

Regular roll appeals run July 2 to September 15. Supplemental, Roll Change, or Escape assessments have 60 days from the notice or postmark. Calamity reassessment has 6 months from the notice.

Step 2: File the application correctly

Use BOE-305-AH. Mail or deliver to the Assessment Appeals Board Clerk (Suite D430). Fee: $65.75 per application/parcel. You may also request written findings for an extra fee if you want a formal write-up of the decision. Properties owned by trusts or LLCs have special signing requirements; read about filing as a couple, trustee, or LLC to avoid dismissals.

Step 3: Prepare for the hearing

SLO uses a three-member Assessment Appeals Board. Hearings are typically in the Board of Supervisors Chambers. The county must hear your appeal within two years of filing; you'll get at least 45 days' notice. You must confirm attendance no later than 21 days before your hearing.

Step 4: Exchange information (optional but smart)

You may request a mutual Exchange of Information no less than 30 days before the hearing. This allows you to review the Assessor's packet before the hearing.

Step 5: Bring admissible evidence

Boards can only consider comparable sales that closed no later than 90 days after the valuation date. For a decline-in-value appeal, that valuation date is January 1 of the year you are appealing. See BOE Publication 30 for more details.

Who has the burden of proof?

For an owner-occupied single-family dwelling, the Assessor has the burden of proof. In most other cases, the applicant does.

DIY evidence checklist that actually works

Assessors reward specific types of evidence and ignore others. We walk through what appeals boards actually care about in a dedicated guide. Many homeowners waste time on documentation that boards ignore; you can avoid those pitfalls by learning about common appeal myths that need busting.

You'll need 3 to 5 recent, truly comparable sales within about a mile, sized and styled like your home, with notes on any adjustments. Sales must respect the 90-day window rule for formal appeals. Include photos and contractor estimates that document condition issues as of January 1. Add a one-page summary that tells the story: where your home trails the comps and why your reconciled opinion of value is reasonable. Optional: make a 30-day Exchange of Information request so you can review the Assessor's packet before the hearing.

Frequently asked questions

Can my assessment jump more than 2 percent in one year?

Yes, if you are on a temporary Prop 8 reduction and market value rebounds. Prop 8 values are re-tested each lien date and can move up or down to market, never above your Prop 13 factored ceiling. To understand upside risks better, take a look at our guide exploring whether appealing can backfire.

Do I need to reapply for a Prop 8 reduction every year?

Nope. Prop 8 reductions are one year at a time. Each January 1 the Assessor must compare your Prop 13 track to market and enroll the lower number. If you disagree with the Assessor's review, file a formal appeal in the regular window.

What if I miss the September 15 filing window?

You lose the ability to challenge the regular roll value for that year. You can still appeal Supplemental, Roll Change, Escape, or Calamity notices within their shorter windows.

Where can I verify parcel and roll information?

Use the county's Property Information Search and related Assessor services.

How AppealArc helps

AppealArc takes no cut of any tax savings from your appeal. It builds clean, lien-date-focused comp sets that boards respect. Our grids show your best 3 to 5 sales, sensible adjustments, and a concise narrative. You get county-specific checklists, date windows, and form pointers, so you can file with confidence and argue like a pro.

Rules are local. Always verify the current instructions with San Luis Obispo County and county's official sites before filing.