List of States without income tax via wikipedia:
Alaska – has a state corporate income tax
Florida – has a state corporate income tax. Once had tax on "intangible personal property" held on the first day of the year (stocks, bonds, mutual funds, money market funds, etc.) but was abolished at the start of 2007. The Florida Constitution explicitly prohibits a personal income tax.
Nevada has no personal or corporate income tax. Nevada gets most of its revenue from gambling taxes.
New Hampshire has an Interest and Dividends Tax of 5%, and a Business Profits Tax of 8.5%.[4]
South Dakota – has a state corporate income tax on financial institutions.
Tennessee – does have tax on income (at a 6% rate) received from stocks and bonds not taxed ad valorem (Tenn Const Art II, §28). The Tennessee Supreme Court has held that a personal income tax is unconstitutional. [Evans v. McCabe]
Texas – in May 2006, passed a franchise tax on businesses (sole proprietorships and some partnerships are exempt). The Texas Constitution places severe restrictions on passage of a personal income tax and use of its proceeds.
Washington – has a Business and Occupation Tax (B&O) on gross receipts, applied to "almost all businesses located or doing business in Washington." It varies from 0.138% for splitting dried peas to 1.6% for bigtime gambling.[5][6]
Wyoming
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Basically Florida and Nevada on that list (w/o income tax, rest do)