B&O tax is overhead
The B&O tax is a tax on the seller and is a part of the seller's overhead. It is not a tax imposed on the buyer and collected by the seller, as is the case with Washington's retail sales tax.
Completing the return
When completing the excise tax return, the amounts reflected in the "gross amount" and "taxable amount" columns for both B&O tax and retail sales tax must include any amounts charged to the buyer for B&O tax.