Why your Seattle bathroom estimate has a 10.55% sales tax line

Your estimate for a Seattle bathroom shows the price of the work and, on its own line, Washington sales tax. In Seattle that tax is 10.55% in the fourth quarter of 2026 (Washington DOR rate flyer, checked October 2026). Washington requires it, and the contractor sends it to the state.

Is there sales tax on a bathroom remodel in Washington?

Yes. A remodel is custom construction, and the Department of Revenue (DOR) says the homeowner pays retail sales tax on the full contract price. The contractor collects it and sends it to the state (DOR custom construction guide, checked October 2026).

The state's building rule says the same: the prime contractor collects the tax from the consumer, and the tax is measured by the full contract price, so labor is taxed too (WAC 458-20-170, checked October 2026).

Why is the tax on its own line?

Because the DOR presumes that a quoted price does not include sales tax unless the tax is separately itemized, and it says the words "tax included" are not enough to meet that rule (DOR custom construction guide, checked October 2026).

So our rule is simple. Washington retail sales tax goes on the estimate as a separate line, at the rate of the project address. You see the price of the work, then the tax, then the total.

The same guide says progress bills should show the tax separately too. If a contractor bills in stages, each bill needs its own tax line.

Which rate do you pay: Seattle, Shoreline, Renton or Bellevue?

The rate is set by the address where the work happens, wherever the contractor's office is. The DOR guide puts it plainly: construction that takes place in Seattle is taxed at Seattle's combined state and local rate (DOR custom construction guide, checked October 2026).

The DOR updates the rates every quarter (DOR rates page, checked October 2026). Here are the combined rates for the 12 cities where we take estimates, from the DOR flyer for October 1 to December 31, 2026 (DOR Q4 2026 flyer, checked October 2026).

Bothell sits in two counties. The Snohomish County part carries a different rate, so the street address matters.

Some cities also have a "Non-RTA" area with a lower rate. Bellevue, Redmond, Renton, Issaquah, Sammamish, Newcastle and Woodinville each have one on the same flyer. If your home might be in one, look up the exact address with the DOR tax rate lookup tool before you compare estimates.

How much does the tax add to a real estimate?

Multiply the contract price by the rate. This is just math, not a quote: every $10,000 of contract price at a Seattle address adds $1,055 of tax (10,000 x 10.55%). At a Bellevue address it adds $1,030.

Seattle versus Bellevue is $25 per $10,000. Two estimates for the same bathroom can differ by thousands. So compare them on the price before tax first, then on the total.

Does the tax change when the scope changes?

Yes, because it rides on the price. A change order raises the contract price, and the tax is measured by the full contract price (WAC 458-20-170, checked October 2026). So the addition carries tax at the project-address rate in force on that date. Ask to see it as its own line, the same way the original estimate shows it.

How do you check your own estimate?

Four checks. Do them on any estimate you hold, ours included.

1. Find the tax line. It should be its own line under the price of the work.
2. Check the address the rate was figured for. It should be the house you are remodeling.
3. Look up that address on the DOR tool and compare the rate.
4. Multiply the price of the work by the rate. That number should equal the tax line, and price plus tax should equal the total.

If the numbers do not match, ask. A good contractor will walk you through it. For how we price the work itself, see our pricing section. To get a written price with the tax line, call +1 206-222-2328 or email [email protected].