Orange County, CA: Property Tax Appeal Instructions (2025-26)

If your Orange County tax bill gave you sticker shock, take a breath. You do not need a law degree or a crystal ball. You just need the right deadlines, the right form, and the right comps.

Key facts at a glance

Filing window and instructions for informal reviews, required mailing, and "no-charge" language come from the Assessor's site. The formal appeal window for 2025, original-signature requirement, mailing and in-person addresses, and phone/email are from the Clerk of the Board.

Property owners in other California counties can find their county-specific deadlines and procedures here.

New to property tax appeals? Start with the fundamentals in our Appeal 101 article, which covers the core concepts that apply across California.

The 60-second primer

Prop 13 sets your base-year value and typically limits annual increases to up to 2 percent. That is why longtime owners often pay less. When market prices jump, your assessed value usually does not follow at the same pace, according to the Orange County Assessor. Our Property Tax Appeal, Explained Like I'm a Homeowner article walks through these concepts in more detail.

Prop 8 (Decline-in-Value) allows a temporary reduction when market value on January 1 is lower than your Prop 13 factored value. When the market recovers, the Assessor can restore value up to your Prop 13 track, as explained by the Orange County Assessor.

The Orange County "Informal" route (Prop 8 review)

Best for: You believe your home's January 1, 2025 market value was lower than the value on your notice.

1. Check your enrolled value

Look up your parcel and the value the county is using to tax you. Then compare to recent closed sales. The county's Find My Assessed Value tool and your annual value notice explain what is on the roll.

2. Build credible comps for January 1

Use closed sales near your home that bracket the lien date. California boards can only consider sales up to 90 days after January 1, per BOE Publication 30. Sales closest to that date carry the most weight. Aim for at least three. How Comparable Sales Work explains the process of finding properties, making adjustments, and presenting your analysis. Understanding what makes evidence persuasive ensures you focus on documentation that actually moves the needle.

3. Submit the Assessor's informal review request by April 30

Pick the correct property-type form, fill it out carefully, print, and mail to the P.O. Box shown on the form. The Assessor does not charge for this review.

4. Watch your mailbox in July

The Assessor mails Value Notices in July. If you still disagree, file a formal appeal during the regular period.

The Orange County "Formal" route (Assessment Appeal)

Best for: You missed the informal window, tried it and still disagree, or you received a supplemental/escape assessment. Not sure which route fits your situation? Informal vs. Formal Appeal: Which Should You Try First? breaks down the pros and cons of each approach.

1. Know your deadline

For the 2025 regular roll, the filing period is July 2 to December 1, 2025, according to the OC Clerk of the Board. If you received a supplemental or escape assessment notice, you generally have 60 days from that notice to appeal.

2. File correctly

Start with the Online Assessment Appeal Application, then print, sign, and mail or deliver the application by the deadline. Original signature is required. No fee to file. Mail to P.O. Box 22023, Santa Ana, CA 92702 or file in person at 400 W. Civic Center Dr., Room 110, Santa Ana, CA 92701. Questions: (714) 834-2331 ext. 1 or [email protected]. Properties owned through trusts or entities need special attention—review signing requirements for trusts and LLCs to avoid dismissal for lack of standing.

3. Choose your venue

You may select a Hearing Officer (1 person, residential cases, faster and informal) or a 3-member Appeals Board (more formal). If you want Findings of Fact, you must choose the full Board.

4. Exchange information, if helpful

California R&T §1606 and Property Tax Rule 305.1 allow a pre-hearing Exchange of Information so both sides see the valuation basis. This can streamline your hearing.

5. Bring the right evidence

For residential appeals, bring at least six sets of your comps for the hearing. The Board cannot consider sales more than 90 days after January 1, per the Clerk of the Board. Evidence closest to January 1 is strongest.

6. What happens next

Hearings usually start in the months after filing. A decision may be announced at the hearing or mailed later. If you win, the Auditor-Controller processes any refund.

DIY evidence checklist

Gather 3 to 6 closed sales, same neighborhood and property type, near January 1, 2025. Avoid pendings and actives, per the Clerk of the Board. Create a one-page grid that adjusts for beds, baths, size, condition, lot, view, and time. Include support showing condition: photos, inspection notes, quotes for needed repairs. If you recently bought the home, include the closing statement and explain concessions. Craft a short "story" that ties the evidence to January 1 and to a single opinion of value. Finally, prepare six printed sets for the hearing.

FAQ

Should I try the informal review first?

Yes, if you can meet the April 30 informal deadline. It is free and designed for Prop 8 decline-in-value requests. If you miss it or disagree with the result, use the formal appeal window. The trade-offs between each path are covered in detail in Informal vs. Formal Appeal: Which Should You Try First?.

I heard Orange County's appeal period runs through late fall. What are the exact 2025 dates?

For 2025, the filing period is July 2 to Monday, December 1, 2025 because November 30 is a Sunday, per the OC Clerk of the Board.

Does Orange County charge a filing fee?

No. There is no fee to file an assessment appeal. The Clerk notes small fees only for optional records or audio copies.

Can I submit my appeal entirely online?

You must still print, sign, and mail or deliver the application even if you complete it online. The original signature is required.

What comps will the Board accept?

Closed sales near January 1. By law, the Board cannot consider sales more than 90 days after the lien date, per BOE Publication 30. Closer is better. If you need help with the selection and adjustment process, How Comparable Sales Work covers it step by step.

Will my value go up if I appeal?

Boards must find fair market value from the evidence presented. In rare cases, that can be higher than the enrolled value. Be prepared with solid, lien-date-focused support. This concern comes up often, and Will Appealing Backfire? The Upside Risk, Plainly Stated addresses when it actually happens and how to avoid it. Many homeowners worry unnecessarily about this—read about other persistent myths that stop people from pursuing valid appeals.

How long until I get a hearing?

If you file near July, hearings often begin in the fall with many residential matters heard within several months. Your exact timing varies based on volume.

What if my notice was a supplemental or escape assessment?

Those have a 60-day appeal window from the date on the notice. Do not wait for the regular period.

Key Orange County reminders

Informal review window is short: Jan 1 to Apr 30. Plan early.

Original signatures matter for formal appeals even if you start online.

Bring six copies of your evidence to the hearing.

Hearing Officer vs Board: Choose Board if you want Findings of Fact.

Prop 13 isn't a blanket freeze: most years your taxable value increases by up to 2 percent unless Prop 8 applies.

How AppealArc helps Orange County homeowners

AppealArc provides a fast value check by lining up the right January 1 comps and screening out anything outside the 90-day rule. We deliver a polished packet with a detailed comp grid, exhibits, and a convincing narrative that an Assessor can absorb in minutes.

Rules are local. Always verify the current instructions with OC Clerk of the Board and Orange County's official sites before filing.