Section 43.20.040 - Income from sources in the state(a) In this chapter, income from sources in the state includes (1) income from real or tangible personal property located in the state;(2) income of whatever nature from a business, trade or profession having a business situs in the state and compensation for services rendered in the state;(3) income from stocks, bonds, notes, bank deposits, and other intangible personal property having a taxable or business situs in the state;(4) rentals and royalties for the use of or for the privilege of using, in the state, patents, copyrights, secret processes and formulas, good will, marks, trade brands, franchises, and other property having a taxable or business situs in the state.(b) In this section, income is from a source having a taxable or business situs in the state if it is derived from (1) owning or operating business facilities or property in the state;(2) conducting business, farming, or fishing operations in the state;(3)[Repealed, Sec. 10 ch 1 SSSLA 1980].(4) a partnership which transacts business in the state;(5) a corporation which transacts business in the state which has elected to file federal returns under subchapter S of the Internal Revenue Code;(6)[Repealed, Sec. 10 ch 1 SSSLA 1980].(7) engaging in any other activity from which income is received, realized or derived in the state.(c) The receipt of income derived solely from interest earned on property in the state does not alone establish a taxable or business situs in the state.