(a) In addition to all other taxes now imposed by law, there is hereby levied and imposed a tax on the taxable income, as defined in this chapter, which tax shall be assessed, collected, and paid annually at the rate specified herein and for each taxable year as hereinafter provided. Persons and subjects taxable under this chapter are:
(1) Every individual residing in Alabama.
(2) Every corporation domiciled in Alabama or licensed or qualified to transact business in Alabama.
(3) Every corporation doing business in Alabama or deriving income from sources within Alabama, including income from property located in Alabama.
(4) Every nonresident estate or nonresident trust receiving income from property owned or business transacted in Alabama.
(5) Every resident estate and resident trust.
(6) Every nonresident individual receiving income from property owned or business transacted in Alabama.
(b) Every natural person domiciled in the State of Alabama, and every other natural person who maintains a permanent place of abode within the state or spends in the aggregate more than seven months of the income year within the state, shall be presumed to be residing within the state for the purposes of determining liability for income taxes under this chapter.