California decline-in-value review

Are you overpaying your property tax?

If your home is worth less than the county's assessed value, California law lets you lower your tax bill. Checking is free, and your taxes can only go down, never up.

★★★★★ So smooth and automated 🎉 My reduction was approved in 3 days 💸 I saved $3,500
No obligation. Takes about a minute. Your information stays private.
1

Tell us your address

We pull your parcel and assessed value straight from county records.

2

We build your case

Recent sales of homes like yours, screened against the county's evidence rules.

Comparable sales work sheet
PER BOE PUBLICATION 30
SubjSale 1Sale 2
Living area2,3682,1042,682
Beds / baths5/34/34/3
Size adj-+11%-10%
Adjusted-$1.69M$1.89M
3

Done in 2 minutes.

We file it and track it to the county, then watch for the decision.

Your filing status
Form signed✓ signed
Sent to County Assessor✓ delivered
Assessor's decisionby fall
Now serving 4 California counties
💻Santa Clara· file by 8/8!⛰️Contra Costa· file by 11/26🌳Alameda· file by 12/26🌉San Mateo· file by 10/26💻Santa Clara· file by 8/8!⛰️Contra Costa· file by 11/26🌳Alameda· file by 12/26🌉San Mateo· file by 10/26💻Santa Clara· file by 8/8!⛰️Contra Costa· file by 11/26🌳Alameda· file by 12/26🌉San Mateo· file by 10/26

Don't see your county? Request it here

What homeowners are saying
Real filings, real savings, from our pilot.
My assessor's office called to say my reduction was approved. I'm saving $3,500 in property taxes this year. 🎉
Contra Costa homeowner
Not all heroes wear capes. Thank you! 👍
Bay Area homeowner
The website was well designed and fluid.
Bay Area homeowner
Nice to see the comps. I don't have to do it manually myself.
Bay Area homeowner
This is cool. I'll definitely come back and use it.
Bay Area homeowner
Loved the website.
San Ramon homeowner
Awesome, and quite accurate.
Bay Area homeowner

Filed with us and got a result? Tell us how it went →

Most homeowners never claim this benefit.

When your home's value drops below its assessment, the county must lower it: free, and your right by law. But the rules are buried in a 25-page state manual, so most owners never claim it. We handle all of it, by the state's official Publication 30.

1 · Estimate 2 · Confirm 3 · File
Is this legitimate?

Yes. California Revenue and Taxation Code section 51 requires the Assessor to temporarily lower your assessed value when it exceeds your home's market value on January 1. Every county runs a free review process for this. We prepare the county's own form with evidence that follows the state's published rules, and you sign it.

How do you decide my home's value?

We look at every recent, arm's-length sale of a similar home in your own city, not a neighboring town, since a county appraiser treats a different city as a different market. We adjust each of those sales to your home for the differences that matter: living-area size, bedrooms, bathrooms, age, and lot. Your opinion of value is the median of the adjusted sales, so no single unusual sale can swing it. The three sales we put on your form are the strongest and most similar of them, the ones an appraiser is least likely to challenge.

How does your evidence follow the county's rules?

California assessors weigh residential evidence by State Board of Equalization Publication 30, the official guide for these reviews. It calls recent, arm's-length sales of similar homes the most reliable evidence, adjusted for real differences and dated near January 1. That is exactly what we build: same-city sales within the valuation window the law requires, each adjusted to your home for size, bedrooms, bathrooms, age, and lot, presented on the state's own comparison work sheet so the appraiser can check every figure. We deliberately do not adjust for things public records cannot confirm, such as condition or view, because an unsupported adjustment invites a challenge.

What do I actually get, and what does the filing look like?

You get a complete, ready-to-file package, not just a number. It is the county's own review form, filled in, plus a professional comparable-sales work sheet in the format the state's appraisers use. The work sheet places your home next to the comparable sales, side by side, and shows line by line how each sale was adjusted to yours for size, bedrooms, bathrooms, age, and lot. It is the kind of exhibit a private appraiser or tax agent would charge hundreds of dollars to prepare. You review it, sign once, and we send it to the county. In counties that use an online portal, we hand you the same package to upload in about two minutes.

What does it cost?

Nothing. The county's review itself is a free service the state provides, and SavePropTax is free during our pilot.

Is there any downside or risk?

No. There is no fee, no penalty, and no risk in asking: the review can lower your assessed value or leave it unchanged. A decline-in-value review cannot raise your Prop 13 base value, and next year's assessment is set the same way whether or not you file.

What if the county says no?

Nothing changes: your taxes stay exactly as they are. You can also escalate to a formal appeal with the county's appeals board until November 30, and we will guide you through that too.

How is a review different from an appeal, and will I have to appear anywhere?

A decline-in-value review is an informal request, not an appeal. You give the Assessor your opinion of value and comparable sales, and a county appraiser reviews it on paper. There is no hearing and nothing to attend. A formal appeal is a separate, later step that only comes up if the Assessor's review does not lower your value and you disagree with that result. That one goes to the county's Assessment Appeals Board and can involve a hearing. Most homeowners never need it, and we will walk you through it if you do.

Is my information safe?

Your details are used once to prepare your form and are not sold or shared. Your signed form goes to the County Assessor and to you, nobody else.

Still have a question? Email support@saveproptax.com.