To tax (from the latin taxare: to estimate, which in turn is from tangere: to touch) is to impose a financial charge or other levy upon a taxpayer (an individual or legal entity) by a state or the functional equivalent of a state.

Taxes are also imposed by many subnational entities. Taxes consist of direct tax or indirect tax, and may be paid in money or as its labour equivalent (often but not always unpaid). A tax may be defined as a "pecuniary burden laid upon individuals or property to support the government 1 a payment exacted by legislative authority."Black's Law Dictionary, p. 1307 (5th ed. 1979). A tax "is not a voluntary payment or donation, but an enforced contribution, exacted pursuant to legislative authority" and is "any contribution imposed by government 2 whether under the name of toll, tribute, tallage, gabel, impost, duty, custom, excise, subsidy, aid, supply, or other name."

In modern taxation systems, taxes are levied in money, but in-kind and corvée taxation are characteristic of traditional or pre-capitalist states and their functional equivalents. The method of taxation and the government expenditure of taxes raised is often highly debated in politics and economics. Tax collection is performed by a government agency such as Canada Revenue Agency, the Internal Revenue Service (IRS) in the United States, or Her Majesty's Revenue and Customs (HMRC) in the UK. When taxes are not fully paid, civil penalties (such as fines or forfeiture) or criminal penalties (such as incarceration) may be imposed on the non-paying entity or individual.

Purposes and effects

Funds provided by taxation have been used by states and their functional equivalents throughout history to carry out many functions. Some of these include expenditures on war, the enforcement of law and public order, protection of property, economic infrastructure (roads, legal tender, enforcement of contracts, etc.), public works, social engineering, and the operation of government itself. Most modern governments also use taxes to fund welfare and public services. These services can include education systems, health care systems, pensions for the elderly, unemployment benefits, and public transportation. Energy, water and waste management systems are also common public utilities. Colonial and modernizing states have also used cash taxes to draw or force reluctant subsistence producers into cash economies.

Governments use different kinds of taxes and vary the tax rates. This is done to distribute the tax burden among individuals or classes of the population involved in taxable activities, such as business, or to redistribute resources between individuals or classes in the population. Historically, the nobility were supported by taxes on the poor; modern social security systems are intended to support the poor, the disabled, or the retired by taxes on those who are still working. In addition, taxes are applied to fund foreign and military aid, to influence the macroeconomic performance of the economy (the government's strategy for doing this is called its fiscal policy - see also tax exemption), or to modify patterns of consumption or employment within an economy, by making some classes of transaction more or less attractive.