section_path: Types/Income Taxation/Income tax
section_name: Income tax
paragraph_text: Income tax
  
  Many jurisdictions tax the income of individuals and of business entities, including corporations. Generally, the authorities impose a tax on net profits from a business, on net gains, and on other income. Computation of income subject to tax may be determined under accounting principles used in the jurisdiction, which tax-law principles in the jurisdiction may modify or replace. The incidence of taxation varies by system, and some systems may be viewed as progressive or regressive. Rates of tax may vary or be constant (flat) by income level. Many systems allow individuals certain personal allowances and other non-business reductions to taxable income, although business deductions tend to be favored over personal deductions.
  
  Tax-collection agencies often collect personal income tax on a pay-as-you-earn basis, with corrections made after the end of the tax year. These corrections take one of two forms:
  
  Income-tax systems often make deductions available that reduce the total tax liability by reducing total taxable income. They may allow losses from one type of income to count against another – for example, a loss on the stock market may be deducted against taxes paid on wages. Other tax systems may isolate the loss, such that business losses can only be deducted against business income tax by carrying forward the loss to later tax years.