Beginning Jan. 1, 2020 the nexus threshold for all B&O tax classifications and sales tax collection will be $100,000 of combined gross receipts per calendar year for businesses without a physical presence. Physical presence will also establish nexus for all B&O tax classifications and sales tax collection (SSB 5581).
Economic nexus is a nexus standard based on meeting one or more economic nexus thresholds for receipts, payroll, and property. If an out-of-state business has economic nexus, it must get a Washington tax registration.
For more information on the economic nexus thresholds for wholesale sales, retail sales and apportionable activities see:
Effective July 1, 2017, the timeframe for determining whether a business has exceeded any of the economic nexus thresholds includes both the current year and immediately preceding year (EHB 2163, Chapter 28, Laws of 2017).
Remote sellers meeting either retail sales tax threshold may be required to register and collect/submit retail sales tax on sales made to Washington consumers.
For more information, see Marketplace fairness.