Income tax

An income tax is a government levy (tax) imposed on individuals or entities (taxpayers) that varies with the income or profits (taxable income) of the taxpayer. Details vary widely by jurisdiction. Many jurisdictions refer to income tax on business entities as companies tax or corporate tax. Partnerships generally are not taxed; rather, the partners are taxed on their share of partnership items. Tax may be imposed by both a country and subdivisions. Most jurisdictions exempt locally organized charitable organizations from tax.

Income tax generally is computed as the product of a tax rate times taxable income. The tax rate may increase as taxable income increases (referred to as graduated rates). Tax rates may vary by type or characteristics of the taxpayer. Capital gains may be taxed at different rates than other income. Credits of various sorts may be allowed that reduce tax. Some jurisdictions impose the higher of an income tax or a tax on an alternative base or measure of income.

Income tax in the United States

In the United States, a tax is imposed on income by the federal, most state, and many local governments. The income tax is determined by applying a tax rate, which may increase as income increases, to taxable income as defined. Individuals and corporations are directly taxable, and estates and trusts may be taxable on undistributed income.

Partnerships are not taxed, but their partners are taxed on their shares of partnership income. Residents and citizens are taxed on worldwide income, while nonresidents are taxed only on income within the jurisdiction. Several types of credits reduce tax, and some types of credits may exceed tax before credits. An alternative tax applies at the federal and some state levels.

Taxable income is total income less allowable deductions. Income is broadly defined. Most business expenses are deductible. Individuals may also deduct a personal allowance (exemption) and certain personal expenses, including home mortgage interest, state taxes, contributions to charity, and some other items. Some deductions are subject to limits.

Income tax in Australia

Income tax in Australia is the most important revenue stream within the Australian taxation system. Income tax is levied upon three sources of income for individual taxpayers: personal earnings (such as salary and wages), business income and capital gains. Collectively these three sources of income tax account for 67% of federal government revenue and 55% of total revenue across the three tiers of government.

Income received by individuals is taxed at progressive rates, while income derived by companies is taxed at a flat rate of 30%. Generally, capital gains are only subject to tax at the time the gain is realised. Income tax is collected by the Australian Taxation Office on behalf of The Commissioner of Taxation.

In Australia the financial year runs from 1 July to 30 June of the following year. Income tax is applied to the taxable income of a taxable entity. Taxable income is calculated, in a broad sense, by applying allowable deductions against the assessable income of a taxable entity.