Also, WI and IL have tax reciprocity for W-2 income. WI residents who work in IL are not subject to IL income tax on their W-2 income.
Bottom line: once you move to WI your income is subject to WI state income tax regardless of where you earn it. As @xmasbaby0 said, if your employer cannot withhold WI income tax for you, then you must make quarterly estimated tax payments to WI.
https://www.revenue.wi.gov/Pages/FAQS/pcs-estpay.aspx
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
