If you earned wages, salaries, tips, or other employee compensation from an employer in Iowa, Kentucky, Michigan, or Wisconsin while you were a resident of Illinois, you're covered by a reciprocal agreement between that state and Illinois and aren't taxed by that state on your compensation. However, you may be taxed on other income.
If your employer withheld taxes or you paid tax to these states on your compensation, you must claim a refund from that state. You may not claim a credit on Illinois Schedule CR for that tax. You must file the appropriate forms with that state to receive a refund of taxes withheld in error.
The reciprocal agreements don't prohibit subdivisions of these states from imposing a tax on your compensation. For example, if you were subject to tax by a city in Kentucky while you were an Illinois resident, you may claim a credit for that local tax.
In addition, because of differences in state laws, you may be considered a resident by one of these states and required to pay their income taxes, even though you're an Illinois resident under Illinois law. In that case, you may claim a credit for the taxes paid.