Washington Revised Code Title 82. Excise Taxes § 82.04.4283. Deductions--Cash discount taken by purchaser

In computing tax there may be deducted from the measure of tax the amount of cash discount actually taken by the purchaser. This deduction is not allowed in arriving at the taxable amount under the extractive or manufacturing classifications with respect to articles produced or manufactured, the reported values of which, for the purposes of this tax, have been computed according to the provisions of RCW 82.04.450.