California Property Tax Appeal
How to Appeal Your Property Taxes in San Diego County (2026)
San Diego County's housing market climbed hard for years, and county assessments climbed with it. When prices flatten or dip in a neighborhood, the assessed value on your bill doesn't automatically follow — it stays where the last upswing left it until someone asks for a correction. For a lot of San Diego owners, that gap is real money left on the table.
San Diego makes the first step easy: the Assessor accepts an informal value-review request before you ever file a formal appeal. If comparable homes near you have sold for less than your assessed value, that informal review is often all it takes. One local quirk to plan around — San Diego requires an original, wet-ink signature on the formal application; no faxes or digital signatures are accepted.
Below is exactly how an appeal works here — the December 1 deadline, the form, the fee, and the informal-first path — plus an honest read on whether your assessment is actually too high in the first place.
San Diego County appeal — at a glance
- Appeal deadline
- July 2 – December 1
- Filing fee
- Varies — contact clerk
- Appeal form
- BOE-305-AH
- Assessor's office
- (619) 237-0502
Check your San Diego County home in minutes
Enter your address and get an honest, comparable-sales analysis of whether you're overassessed — $9.99, with 3 years of monitoring included.
Analyze my assessmentFlat fee. You keep 100% of your tax savings.
Is your San Diego County home overassessed?
California property tax bills run roughly 1.1%–1.25% of a home's assessed value. At that rate, an assessment that's $50,000 too high costs a homeowner on the order of $550–$625 every single year — and it compounds until someone corrects it.
The only way to know is to compare your assessed value against what similar nearby homes actually sold for. That's exactly what a Numa analysis does: real comparable sales, an honest overassessed / fairly-assessed verdict, and a conservative savings estimate — for $9.99, with 3 years of monitoring included.
How to appeal in San Diego County, step by step
- 1
Confirm your home is overassessed
Your case rests on recent sales of comparable homes. Gather a few similar properties nearby that sold recently, adjust for differences in size, age, and condition, and check whether they came in below your assessed value. This is the most time-consuming part of an appeal, and the quality of those comparables is what decides it.
- 2
Request an informal review with the Assessor
In San Diego County, start with an informal Decline-in-Value (Proposition 8) review — often the fastest path, resolved without a hearing. Contact (619) 237-0502 for the informal review process..
- 3
File a formal appeal if needed
If the informal review doesn't resolve it, file form BOE-305-AH with the Assessment Appeals Board — before the December 1 deadline. You can file by mail or in person.
- 4
Present your evidence
Your comparable-sales evidence is what wins the appeal. Numa's $24.99 packet assembles it into a ready-to-file case — and if the informal review fails, the formal Appeals Board packet is included at no extra charge.
Do it yourself, or let Numa do the hard part
You can absolutely appeal on your own — the deadline, form, and steps above are all you need to file. The catch is Step 1: building the comparable-sales evidence that actually wins. Here's the honest trade-off.
Do it yourself
- Free
- Typically 5–10 hours of work
- You find, adjust, and score the comps yourself
- Amateur evidence is the top reason appeals fail
- No easy way to know if you should file at all
With Numa
- $9.99 analysis, done in minutes
- Real comparable sales, scored the way the county does
- An honest verdict — including “don't file, you're fairly assessed”
- 3 years of monitoring included
- Optional $24.99 ready-to-file evidence packet if you're overassessed
San Diego County key dates
- Appeal window: July 2 – December 1
- Original signature required — no faxes or digital signatures accepted. Prop 8 informal review must be filed by April 30 with the Assessor's Office.
- Prop 8 (decline in value): Informal review with Assessor: December 1 – April 30. Formal appeal same as regular deadline.
San Diego County property tax appeal — FAQ
What is the property tax appeal deadline in San Diego County?
The regular appeal window runs July 2 through December 1. Original signature required — no faxes or digital signatures accepted. Prop 8 informal review must be filed by April 30 with the Assessor's Office.
How much does it cost to appeal property taxes in San Diego County?
The filing fee varies — contact the clerk of the board for the current amount.
Do I have to go to a hearing to lower my assessment?
Often not. In San Diego County you can request an informal review (a Decline-in-Value / Proposition 8 request) with the Assessor first — many reductions are resolved this way without a formal hearing. If the informal review doesn't succeed, you can file a formal appeal with the Assessment Appeals Board.
How do I know if my San Diego County home is overassessed?
Your home is overassessed if comparable homes recently sold for less than your assessed value. Numa runs that comparison for you — the same comparable-sales method the county uses — and gives you an honest verdict for $9.99, with 3 years of monitoring included.
What form do I use to appeal in San Diego County?
Formal appeals use form BOE-305-AH, filed with the Assessment Appeals Board. Numa's packet fills in the evidence and shows you exactly how to file it.
Check your San Diego County home in minutes
Enter your address and get an honest, comparable-sales analysis of whether you're overassessed — $9.99, with 3 years of monitoring included.
Analyze my assessmentFlat fee. You keep 100% of your tax savings.