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
Dual income tax Dual income tax The dual income tax system levies a proportional tax rate on all net income (capital, wage and pension income less deductions) combined with progressive tax rates on gross labour and pension income. This implies that labour income is taxed at higher rates than capital income, and that the value of the tax allowances is independent of the income level. The dual income tax system deliberately moves away from the comprehensive income tax (global income tax) system which taxes all or most (cash) income less deductions (net income) according to the same rate schedule. The dual income tax