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.
Illinois' income tax rates were last changed two years prior to 2015 for tax year 2013, and the tax brackets have not been changed since at least 2001. Illinois has a flat income tax rate which applies to both single and joint filers.