Washington Revised Code Title 82. Excise Taxes § 82.04.530. Telecommunications service providers--Calculation of gross proceeds

For purposes of this chapter, a telecommunications service provider other than a mobile telecommunications service provider must calculate gross proceeds of sales in a manner consistent with the sourcing rules provided in RCW 82.32.520. The department may adopt rules to implement this section, including rules that provide a formulary method of determining gross proceeds that reasonably approximates the taxable activity of a telephone business.