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
Income tax in the United States of which is also to be withheld from wages. Withholding of income and Social Security taxes are often referred to as payroll tax. Individuals (with income above a minimum level), corporations, partnerships, estates, and trusts must file annual reports, called tax returns, with federal and appropriate state tax authorities. These returns vary greatly in complexity level depending on the type of filer and complexity of their affairs. On the return, the taxpayer reports income and deductions, calculates the amount of tax owed, reports payments and credits, and calculates the balance due. Federal individual, estate, and trust income tax returns are