Income tax return for taxation also vary, making comparisons all the more difficult. Countries that tax income generally use one of two systems: territorial or residential. In the territorial system, only local income – income from a source inside the country – is taxed. In the residential system, residents of the country are taxed on their worldwide (local and foreign) income, while nonresidents are taxed only on their local income. In addition, a very small number of countries, notably the United States, also tax their nonresident citizens on worldwide income. Countries with a residential system of taxation usually allow deductions or credits
State income tax particularly with respect to partnerships. Most states require taxpayers to make quarterly payments of tax not expected to be satisfied by withholding tax. All states impose penalties for failing to file required tax returns and/or pay tax when due. In addition, all states impose interest charges on late payments of tax, and generally also on additional taxes due upon adjustment by the taxing authority. Forty-three states impose a tax on the income of individuals, sometimes referred to as personal income tax. State income tax rates vary widely from state to state. The states imposing an income tax on individuals tax