Article I of the United States Constitution created and empowered our legislative branch of government. The United States Congress leads the legislative branch. Congress includes both the House of Representatives and the Senate. Generally speaking, Congress makes our laws.
Income Tax returns and schedules. The Illinois Business Income Tax rate for tax years. ending on or after December 31, 2015, is 5.25 percent. (.0525) for taxpayers taxed as corporations, and 3.75. percent (.0375) for taxpayers taxed as trusts or estates. The instructions for overpayments to be carried forward.
For the current income tax rate, see Income Tax Rates. For more detailed information and the Illinois withholding tax amounts, see Booklet IL-700-T, Illinois Withholding Tax Tables. Important: Per PA 100-22, effective July 1, 2017, the Illinois income tax rate increased from 3.75% (.0375) to 4.95% (.0495). Filing and Payment Requirements