Income tax in the United States increase complexity, irrespective of the system's flatness or lack thereof. Income tax is also levied by most U.S. states and many localities on individuals, corporations, estates, and trusts. These taxes are in addition to federal income tax and are deductible for federal tax purposes. State and local income tax rates vary from 1% to 16% of taxable income. Some state and local income tax rates are flat (single rate) and some are graduated. State and local definitions of what income is taxable vary highly. Some states incorporate the federal definitions by reference. Taxable income is defined separately and differently for
Income tax in the United States individuals and corporations in some jurisdictions. Some states impose alternative or additional taxes based on a second measure of income or capital. States and localities tend to tax all income of residents. States and localities only tax nonresidents on income allocated or apportioned to the jurisdiction. Generally, nonresident individuals are taxed on wages earned in the state based on the portion of days worked in the state. Many states require partnerships to pay tax for nonresident partners. Tax returns are filed separately for states and localities imposing income tax, and may be due on dates that differ from federal due