Income tax the discussion of taxation by the United States of foreign persons. Residents, however, are generally subject to income tax on all worldwide income. A very few countries (notably Singapore and Hong Kong) tax residents only on income earned in or remitted to the country. Residence is often defined for individuals as presence in the country for more than 183 days. Most countries base residence of entities on either place of organization or place of management and control. The United Kingdom has three levels of residence. Most systems define income subject to tax broadly for residents, but tax nonresidents only on
Working Tax Credit significant levels of overpayments. In order to reduce the overpayment problem, the income disregard was raised tenfold from £2,500 to £25,000 with effect from 2006/07. Income for tax credit purposes is "in principle" assessed similarly to UK income tax. Thus 'income' (c/f 'taxable income') consists of what the individual receives from gross earned and unearned sources—less allowances for 'expenditures' that would reduce that income. But, unlike income tax, tax credits measure income based on family 'household', rather than the individuals within. Also the effect of "income disregard" —to mask large annual increases in resources from reassessment— weakens comparisons with a