Washington Sales Tax Nexus Thresholds — 2026
Last updated: April 2026
Researched by the NexusFlag Research Team
Washington requires remote sellers to collect and remit sales tax once they exceed $100,000 in annual gross revenue from Washington customers within a calendar year.
Source: Washington Department of RevenueWashington Nexus Threshold Details
Annual gross sales to in-state customers
Number of separate taxable transactions
Nexus triggers when EITHER threshold is crossed first
How sales into the state are counted
Whether Amazon/marketplace sales count toward threshold
Year the economic nexus law took effect
How quickly you must register after nexus is triggered
How often returns are typically due at low volume
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Frequently asked questions about Washington sales tax nexus
When does economic nexus trigger in Washington?
Washington economic nexus triggers when a remote seller exceeds $100,000 in revenue from Washington customers within a calendar year. Once triggered, the seller must register with the Washington Department of Revenue and begin collecting and remitting sales tax.
How long do I have to register after crossing nexus in Washington?
Washington requires sellers to register within 30 days of crossing the economic nexus threshold. Failing to register on time may result in back taxes, interest, and penalties assessed by the Washington Department of Revenue.
Do marketplace sales count toward Washington's nexus threshold?
Washington generally excludes marketplace-facilitated sales from the economic nexus threshold calculation, because the marketplace is responsible for collecting and remitting tax on those sales. Only direct sales from your own channels count toward the Washington threshold.
How often do I need to file sales tax returns in Washington?
Washington assigns filing frequency based on your sales volume. New remote sellers typically start on monthly filing. Washington may adjust your frequency over time as your Washington sales volume becomes clearer. Check with the Washington Department of Revenue for your assigned frequency after you register.
Disclaimer: NexusFlag provides informational data about published state nexus thresholds — not tax advice. State laws change frequently. Always verify current Washington threshold requirements with the Washington Department of Revenue or a qualified sales tax professional before making compliance decisions.