What income do I attribute to Washington?

Apportionable classifications list
B&O tax classification definitions (this list includes definitions of both apportionable and non-apportionable classifications)
Economic Nexus Worksheet/Calculator (xls) - open the "Apportionment" tab to use the apportionment calculator
Q&A
General information page

Single factor receipts apportionment - Generally (pdf) (WAC 458-20-19402)
Single factor receipts apportionment - Royalties (pdf) (WAC 458-20-19403)
Single factor receipts apportionment - Financial Institutions (pdf) (WAC 458-20-19404) - applies to tax liability incurred after May 31, 2010
Financial Institutions income apportionment for tax liability incurred before June 1, 2010 (WAC 458-20-14601)
Doing business inside and outside the state for tax liability incurred before June 1, 2010 (WAC 458-20-194)
Second Engrossed Substitute Senate Bill 6143 (pdf)

Minimum nexus thresholds (WAC 458-20-19401)
Single factor receipts apportionment - Generally (pdf) (WAC 458-20-19402)
Single factor receipts apportionment - Royalties (pdf) (WAC 458-20-19403)
Single factor receipts apportionment - Financial Institutions (pdf) (WAC 458-20-19404) - applies to tax liability incurred after May 31, 2010
Financial Institutions income apportionment for tax liability incurred before June 1, 2010 (WAC 458-20-14601)
Doing business inside and outside the state for tax liability incurred before June 1, 2010 (WAC 458-20-194)
Second Engrossed Substitute Senate Bill 6143 (pdf)


		Introduction Washington businesses Businesses outside Washington What income do I attribute to Washington? How do I calculate my taxable Washington income? Conclusion