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 applies to net investment income in excess of certain thresholds. An individual pays tax at a given bracket only for each dollar within that tax bracket's range. The top marginal rate does not apply in certain years to certain types of income. Significantly lower rates apply after 2003 to capital gains and qualifying dividends (see below). Income tax for year 2017: Single taxpayer making $40,000 gross income, no children, under 65 and not blind, taking standard deduction; Note, however, that taxpayers with taxable income of less than $100,000 must use IRS provided tax tables. Under that table for 2016, the