Washington has no personal or corporate income tax, so there is no income return to file. What applies instead is the Business and Occupation tax on gross receipts, plus a capital gains excise tax on high earners. The B&O tax is the recurring Washington filing, and it is owed on revenue regardless of profit.

Does Washington have an income tax?

No. Washington imposes no individual or corporate income tax. It does levy a 7% excise tax on long-term capital gains above an annual standard deduction (278,000 dollars for 2025), with a higher tier above 1 million dollars, but that applies only to a narrow set of high-gain individuals.

What is the Washington B&O tax deadline?

The Business and Occupation tax is filed monthly, quarterly, or annually on the frequency the Department of Revenue assigns. Quarterly filers are due the end of the month following the quarter, on April 30, July 31, October 31, and January 31. Annual filers are due April 15. The B&O tax applies to gross receipts with no deduction for labor, materials, or other costs, so it is owed even in an unprofitable year.

How does a firm handle Washington at scale?

Washington needs no income-return workflow, but the B&O tax is easy to underweight because it is owed on gross receipts even at a loss. Track each client's assigned B&O frequency and screen high-gain individuals for the capital gains excise tax, and the Washington book is covered without anything tied to a federal income date. See how we think about scaling tax prep workflows.

Where do these dates come from?

All deadlines and thresholds here trace to the Washington Department of Revenue. Verify against the source before filing.