Washington Sales Tax Guide for E-commerce Sellers

Rate structure

Washington's state rate is 6.5%; the combined state + local rate ranges from 6.5–10.6%. Sourcing: Destination.

COMPONENTRATENOTES

State rate6.5%My DOR general statewide rate

Local taxes6.5–10.6%State 6.5% + city/county/transit rates by location code; retailing B&O tax is filed on the same excise return.

ReturnCombined Excise Tax ReturnCombined Excise Tax Return (Retailing B&O + Retail Sales Tax + Local)

Economic nexus threshold

You must register and collect once your Washington sales reach $100,000, measured over the previous or current calendar year. There is no transaction-count threshold. 200-transaction test removed 2019-07-01 (retail sales tax); B&O has separate rules. Marketplace sales count toward this threshold even though the marketplace collects for you.

Where you stand: SalesTax50 tests your imported sales against this exact rule and flags Washington as Approaching or Exceeded on your Nexus page — check my nexus free →

Filing frequency

My DOR assigns a filing frequency at registration based on expected tax liability and adjusts it over time. Frequencies used in Washington: Monthly · Quarterly · Annual.

Due dates

Returns are due on the 25th of the month following the period (last day for annual). When the due date falls on a weekend or holiday it moves to the next business day.

Late filing: 9% (1 month), 19% (2 months), 29% (3+ months) of tax due, plus interest.

Marketplace facilitator rules

Since January 2018, marketplace facilitators (Amazon, eBay, Walmart, TikTok Shop) collect and remit Washington tax on your marketplace sales. How Washington treats them:

Who collects?Facilitatoron marketplace orders; you collect on Shopify / your own site.

Count toward nexus?Yesmarketplace + direct sales together determine your threshold status.

Do you still file?YesYes — a registered seller still files, even for periods where all sales were through marketplaces (a zero or marketplace-only return).

How reported?DeductionDeducted (retail sales tax collected by facilitator); B&O still applies.

Direct salesYou collectShopify, your own site, invoices — you collect and remit on your return.

Marketplace treatment changes state by state and year by year — SalesTax50 separates marketplace and direct sales automatically, but confirm with Washington State Dept. of Revenue when in doubt.

Filing portal & AutoFile

Washington returns are filed through secure.dor.wa.gov. Login verification: Text or email code. SalesTax50 AutoFile prepares the Combined Excise Tax Return from your imported sales — you review and approve every return before it is submitted.

FAQ

Do I need a Washington permit if I only sell on Amazon?

If you exceed the $100,000 threshold or have physical presence (including inventory in Washington warehouses), yes — you must register even though Amazon collects for you.

What if I sell on Shopify and TikTok Shop?

TikTok Shop collects as a marketplace facilitator; Shopify does not. You collect on Shopify orders and report both streams on your My DOR return — SalesTax50 separates them automatically.

Does SalesTax50 file Washington returns automatically?

Yes — AutoFile prepares your Combined Excise Tax Return from imported sales; you approve every return before it is submitted, and a $99 one-time state setup configures your existing Washington permit.

What is B&O tax?

Washington's Business & Occupation tax is a gross-receipts tax on the seller, filed on the same combined excise return as sales tax. It is outside SalesTax50's AutoFile scope for now.

This guide is general information for e-commerce sellers, not tax advice. Rates, thresholds and due dates change — confirm with Washington State Dept. of Revenue before relying on them.

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