FREE · NO SIGNUP TO VIEW · KING COUNTY

See How Much You're Overpaying on Property Tax

Enter your King County address. We compare your assessed value to recent comparable sales — straight from county data — and tell you in 30 seconds whether you have a case. If you do, we email you a print-and-mail appeal packet with the BOE petition pre-filled.

30 seconds · No signup to view your report · No credit card, ever

Want to see the packet first? Preview a sample (PDF) →

⚠ King County's appeal deadline is July 1 (or 60 days after your value notice). Pull your report early to leave time to file.

Why most King County homes are over-assessed

Assessments lag the market

King County re-assesses on January 1. If values dropped after, your bill stays high until you appeal.

The Assessor uses bulk models

Mass-appraisal misses neighborhood-specific factors — view, slope, traffic, condition. Roughly half of appeals win.

Filing is a single form

The Board of Equalization takes a one-page petition + a comparable sales analysis. We give you the analysis. You file it.

WHY US, NOT A NATIONAL APPEAL SERVICE

Built for King County. Only King County.

Paid services like Ownwell, AppealDesk, and PADS cover thousands of counties across 30+ states with the same template. We do one county — King County — and we do it deeply.

01

100% focused on King County

National services apply a generic model across every state. Our comp engine, area codes, ZIP-level $/sqft rates, view premiums, and HPI adjustments are all calibrated specifically to King County — the same way the County Assessor and Board of Equalization look at properties here.

02

Same data sources the BOE uses

Reports pull live from the King County Assessor's eReal Property, eSales, and ArcGIS parcel layers — the exact sources the Board of Equalization references at hearing. Your evidence comes from the same well as theirs.

03

Built by King County homeowners

We built this after appealing our own King County assessments and finding that national services either weren't accurate enough for BOE evidence standards, or took a 25–50% cut of our savings. Every feature exists because we needed it ourselves.

04

Free — you keep 100% of the savings

Paid services typically take 25–50% of your first-year reduction (Ownwell, TaxProper), or charge a flat $39–$59 fee for the same appeal packet (PADS, KingCountyTaxAppeal). We take nothing. You get the full evidence report, a pre-filled BOE petition, cover letter, and hearing prep notes — sign the packet and drop it in Certified Mail (~10 minutes, ~$5 postage). You keep every dollar of the reduction — this year and every year forward.

How we compare

National appeal servicesThis site
Coverage1,000s of counties, 30+ statesKing County, deeply
Data sourceGeneric; varies by regionKing County Assessor (official)
Cost$39–$59 flat (PADS, KingCountyTaxAppeal), or 25–50% of savings (Ownwell, TaxProper)Free
Who filesThey file (you sign an authorization)You file (sign packet, Certified Mail, ~10 min)
SignupRequiredNone

How it works

  1. 1. Enter your address

    We look up your parcel in the King County Assessor system in 1 second.

  2. 2. We pull official data

    Assessed value history, sale records, prior appeals, and arms-length comparable sales — all from county sources.

  3. 3. Read your report, then file

    Decide if you have a case. If yes, drop your email and we'll send a print-ready packet — sign it, mail it with Certified Mail, done.

What you get

Two pieces. Both free. The online report is instant; the appeal packet is emailed to you when you ask for it.

1 — Instant online report

No email, no signup. View in 30 seconds.

  • Current assessment + up to 30 years of history (year-over-year jumps flagged)
  • Sale history of your property
  • Any prior BOE appeals on file (and what they settled at)
  • 3–5 comparable arms-length sales nearby on an interactive map, scored by similarity with a 7-dimension adjustment grid
  • Estimated market value and your potential annual tax savings if you appeal

2 — Print-and-mail appeal packet (PDF, emailed)

One bundled PDF with everything the Board of Equalization wants to see.

  • Filing checklist — printable, with boxes to tick
  • Cover letter to the Board of Equalization (dated, signed)
  • Pre-filled BOE Real Property Petition (King County's official form, ~130 fields populated from your data)
  • Full valuation evidence report — comps, adjustment grid, methodology, legal citations
  • Hearing prep notes — common Assessor counter-arguments and suggested responses

Print the packet, sign two pages, and send via Certified Mail ($5 at any USPS counter). Step-by-step mail-filing guide included.

Built on public King County data — nothing else

We pull live from the King County Assessor's eReal Property database, eSales comp tool, and ArcGIS parcel layers. No MLS scraping, no third-party APIs, no signups. Owner/buyer/seller names are stripped per RCW 42.56.070(9).

See if I'm overpaying

Frequently asked questions

How do I appeal my property tax in King County?
File a petition with the King County Board of Equalization by July 1 of the assessment year — or within 60 days of the mailing date printed on your value notice, whichever is later. The simplest path is to mail a signed petition + evidence packet via Certified Mail to 500 Fourth Ave, ADM-LJ-0210, Seattle, WA 98104 (the postmark date is your filing date under RCW 1.12.070). The King County eAppeals online portal and in-person delivery are also accepted. Either way, you must include comparable sales or other evidence showing the assessor's value exceeds true and fair market value.
What is the King County property tax appeal deadline?
July 1 of the assessment year, OR 60 days after the mailing date on your official value notice — whichever is later. Miss it and you forfeit the right to appeal for that cycle.
How much can I save by appealing my property tax?
Nationally, successful appeals reduce assessed value by 8–20%. At King County's ~1.0% effective tax rate, that's roughly $500–$3,000+ per year on a typical Seattle-area home. Savings compound — the lowered value becomes the baseline for future years.
What is the success rate of property tax appeals?
The National Taxpayers Union Foundation puts the national success rate at 40–60% for filed appeals. With strong comparable-sales evidence, success rates rise significantly. Most homeowners never even file, despite a meaningful chance of winning a reduction.
Is it worth appealing my property tax in Seattle?
If your year-over-year assessment jumped sharply or comparable sales in your neighborhood are lower than your appraised value, yes — the appeal is free to file, and a successful 10% reduction on a $1M home saves about $1,000/year, recurring.
Do I need a lawyer or service to appeal?
No. King County's BOE process is designed for self-represented homeowners. You need a one-page petition plus a comparable-sales analysis. This site generates both — petition pre-filled, evidence report bundled into a single PDF you print, sign, and mail — for free.

Read more in our King County property tax appeal guide, step-by-step how to appeal, or how much you can actually save.