RCW 82A.04.030: Tax imposed—Rates.

(1) Beginning January 1, 2028, a tax is imposed on the receipt of Washington taxable income. Only individuals are subject to payment of the tax, which equals 9.90 percent multiplied by an individual's Washington taxable income.

(2) If an individual's Washington taxable income is less than zero for a taxable year, no tax is due under this section.