If you own a business in WA state, you'll need to file excise taxes
If you don't there is a high likelihood the DOR will assess taxes against you. Washington State excise taxes are usually below 1% of gross revenue not as onerous as B & O Taxes, the most common tax. However, if you are selling goods and some services, sales taxes come to play on the local level.
As a business owner, understanding how to handle your tax responsibilities is a key part to your business's success.
Reaching out to a local tax professional or licensed Enrolled Agent (E.A.) like those at Washington Tax Services can offer clarity and direction for how to approach. WATAX has been in business 35+ years helping business (small and large) sort through the noise and confusion around tax requirements and the best path forward.