Amazon now adds Washington state ad tax
Washington now taxes digital advertising. As of October 1, ad platforms are applying sales tax to Sponsored and Display Ads for customers with Washington billing addresses — meaning sellers will see higher costs.
Written by Alex Lamachenka
Head of DemandGen
Published
TL;DR
If you’re running online ads from Washington, there’s a new sales tax in town — and it could hit your margins hard.
Advertisers are now required to charge sales tax on ad spend billed to Washington addresses. It’s part of a broader push to tax digital services in WA.
What changed
It started with a bill — and a billing address.
- In May 2025, Washington passed Senate Bill 5814, expanding sales tax to cover digital and service-based business activities.
- That includes advertising services like online ad production, placement, sponsored ads, and display campaigns.
- Starting October 1, digital ad platforms like Amazon and Meta began charging WA sales tax on ads billed to customers with Washington addresses.
- Currently, the tax applies when the customer’s billing address is in Washington State.
Why this will hit WA-based seller budgets and margins hard
With advertising services now reclassified as taxable retail sales, sellers based in cities like Seattle could see digital ad spend taxed at a combined rate of up to 10.4%.
Here’s how that adds up.
- Let’s say your Q4 digital ad spend budget is $15,000.
- The combined tax in some Seattle districts can now reach 10.4% — made up of 6.5% state, 3.85% city, and 0.90% special district taxes. (Source: TaxCloud Sales Tax Guide to Seattle, June 2025)
- So if you’re billed in Seattle, you could incur an extra $1,560 in tax on that $15,000 spend — with no increase in clicks, reach, or ROI.
That’s not a higher CPC. That’s tax.
And with Black Friday and the holiday season coming, it’s going to eat into margins fast.
Who this affects
- Sellers and advertisers billed in Washington — your digital ad spend now incurs retail sales tax
- Agencies managing ad spend for Washington-based clients — tax is tied to the client’s billing address
- Finance teams forecasting Q4 campaign budgets — this change could skew cost assumptions
- Advertisers outside Washington — you’re not being charged (yet), but other states may follow
Why this matters
This isn’t just a one-off.
It’s part of a growing movement to tax the digital layer of commerce:
- Washington’s bill SB 5814 also expanded retail sales tax to custom software (and maintenance), IT support, staffing, website development, live presentations, and security services
- Amazon is complying, but Comcast filed suit in September 2025, arguing parts of SB 5814 are unconstitutional
- If the lawsuit succeeds, it could delay or overturn parts of the law — but for now, sellers are being charged
- However, if Washington’s new sales tax rules on digital advertising stand, other states may follow WA’s lead and tax digital advertising too. (This is how marketplace facilitator laws started, too — Washington made the first move in 2018, and the rest followed.)
Next steps for sellers
- Check your billing address on Amazon, Meta, and other platforms. If it’s in Washington, you’re now paying sales tax on ads.
- Adjust your Q4 budgets — especially if you’re planning holiday campaigns.
- Double-check billing settings — if you’re working with an agency, confirm which address is on file.
Other US Sales Tax Updates
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