State income tax is imposed with a fixed or graduate rate on taxable income of individuals, corporations, and certain estates and trusts. Taxable income contours closely to federal government taxable income in many states, with limited modifications. The expresses are prohibited from taxing income from federal bonds or perhaps other obligations. Most tax Social Protection benefits or interest income from obligations of this state. Several states need different useful life and methods supply by businesses inside computing the reduction in price for depreciation.