Income tax in the United States dates. Some states permit related corporations to file combined or consolidated returns. Most states and localities imposing income tax require estimated payments where tax exceeds certain thresholds, and require withholding tax on payment of wages. Puerto Rico is treated as a separate taxing entity from the USA; its income tax rates are set independently, and only some residents there pay federal income taxes (though everyone must pay all other federal taxes). The unincorporated territories Guam, American Samoa, and the Virgin Islands also impose income tax separately, under a "mirror" tax law based on federal income tax law. Proposals have been
Income tax Income tax An income tax is a tax imposed on individuals or entities (taxpayers) that varies with respective income or profits (taxable income). Income tax generally is computed as the product of a tax rate times taxable income. Taxation rates may vary by type or characteristics of the taxpayer. The tax rate may increase as taxable income increases (referred to as graduated or progressive rates). The tax imposed on companies is usually known as corporate tax and is levied at a flat rate. However, individuals are taxed at various rates according to the slab in which they fall. Further, the