
Washington B&O Tax in 2026: Gross Receipts, Nexus, Apportionment, and Multistate Pitfalls
Washington's B&O tax is a gross receipts tax with major 2026 changes — a $2 million economic nexus threshold, tiered service rates from 1.5% to 2.1%, and a $2M standard deduction. This guide breaks down activity-based classifications, market-based sourcing, penalty math that can exceed 39%, and the bookkeeping practices that keep multistate sellers audit-ready.










