Service income apportionment is a method of determining the amount of tax due to LFP when business activities occur in more than one location. Below are links to apportionment resources:http://dor.wa.gov/Content/FindTaxesAndRates/BAndOTax/EconomicNexus.aspx
http://dor.wa.gov/Content/FindTaxesAndRates/BAndOTax/ApportionableActivities.aspx