We sell evidence packets for property tax appeals. We looked pretty hard at building one for Snohomish County and we can't, because the sales data the county publishes holds 163 usable single-family sales for 194,488 homes. Your deadline is three weeks away, so here's everything we found, free, including a warning the county is putting out itself.
The Snohomish County Board of Equalization has a notice on its own page saying the deadline printed in some of the letters homeowners have been getting is wrong, and that a win doesn't keep paying in later years the way those letters suggest. Here it is in the county's words.
"The deadline for filing an appeal is NOT July 1, 2026, as stated in some of the solicitation letters."
"Reductions in assessed value do not 'apply to your tax bills going forward'."
It goes on to say a reduction applies once, to the single year of assessed valuation you appealed. That's the whole of it.
So if something came in the mail telling you to hurry because the deadline is July 1, that date's wrong, and you've almost certainly still got time. And if it told you a win keeps paying every year afterwards, that isn't how Washington works. You win the year you appealed, and the next year the assessor values your home again from scratch.
The real deadline is August 25, 2026 at 4:00 PM. File online and your submission has to be timestamped by then. Mail it and it's got to be postmarked by then.
Washington is the state we know best. The legal research is done, the verdict engine is calibrated against real board decisions, and the packet already exists and works for King County. Adding Snohomish should have been the cheapest new coverage available to us, and with a deadline three weeks out it was honestly the obvious thing to build.
So we went and looked at the data. The county publishes a layer called Recent Property Sales, and the description says it covers the present year and the two prior years. Counted on August 4, 2026, here's what's actually in there.
| Sale year | All sales | Single family |
|---|---|---|
| 2024 | 8,795 | 8,268 |
| 2025 | 168 | 163 |
| 2026 | 7 | 4 |
The 2024 sales are spread evenly across all twelve months, which is what a working feed looks like. Then it just about stops dead. Of those 163 single-family sales in 2025, 160 are from January. The rest of the year has eight sales in it, county-wide.
A 2026 assessment is valued as of January 1, 2026, so the sales that describe what your home is worth are the 2025 ones. That leaves 163 sales to cover 194,488 homes. One sale for every 1,193 houses, or about a twelfth of one percent of the housing stock.
You cannot build a comparable sales case out of that, and Washington boards say so. We read 60 recent State Board of Tax Appeals decisions, and thin or dissimilar comparable sets get taken apart one at a time, with the reasons written down. A single sale "may reflect an outlier value and cannot represent an entire market" is a direct quote from one of them. Selling somebody a packet built on whatever happened to sell within 1,193 houses of them would really just be selling them a loss.
But none of this is us saying Snohomish has bad data. In one respect it's actually better than King County's. The county's Improvement Records file carries 85 columns per property, including finished living area, year built, condition, bedrooms, bathroom fixture counts, basement area and finish, garage and deck square footage, fireplaces, roof and heating. King County doesn't publish anything that rich in bulk.
So the ingredients for identifying homes genuinely like yours are all there. It's the sale prices that are missing, and the prices are the whole argument.
The county's got a full five-year sales report, but it sits behind terms of use that restrict commercial use of the data, and we don't think a business should be building a paid product on a file it agreed not to use commercially. Their live sales search runs through a vendor system that needs a login. So both ways around the gap are closed to us.
Filing is free, and Snohomish takes petitions online. You don't need us, and you certainly don't need anybody else.
If your house has real problems, that's your strongest route here. Repair estimates, easements and development restrictions are all things you can document without needing recent sales. In the Washington decisions we read, photographs of specific defects moved values and vague complaints really didn't. One assessor changed a home's condition rating after seeing the owner's photographs of cracked window frames.
We do the full check for King County in Washington, Cook County in Illinois, Cuyahoga and Franklin in Ohio, and every municipality in New Jersey. Most people who run the check get told not to appeal, which is basically the point of the thing.
And if the sales feed catches up, or a clean sales source turns out to be worth paying for, we'll build Snohomish for 2027. The parcel data and the building records are already good, and Washington's law and our packet already exist, so the rest of the work is pretty small. Leave your address on the check page and we'll write to you when it happens.
The deadline, the solicitation letter warning, the quote about reductions not applying going forward, the list of evidence the board considers and the 75-page limit are all quoted from the Snohomish County Board of Equalization page, read on August 4, 2026. The deadline rule itself is RCW 84.40.038, which sets it at the later of July 1 or 60 days after the county mailed your value notice.
Those sales counts were measured by querying the county's own Recent Property Sales layer on August 4, 2026, and the 194,488 figure is the count of active single-family parcels in the county's parcel layer on the same day. Anybody can repeat both queries. The Improvement Records file is published by the county through its GIS portal and was last updated July 30, 2026.
Also, the board decision quotes come from our reading of 60 recent Washington State Board of Tax Appeals decisions, described in more detail in what actually happens to King County property tax appeals.
Finally, we haven't named any company in this article. The county's notice says "some of the solicitation letters" and we've no way to know which ones, so we've reported what the county published and left it there.