If you’re an Illinois resident and a W2 employee who works in Wisconsin, your work income is not subject to Wisconsin income tax. Therefore you cannot claim an “other state credit” from Illinois.
If Wisconsin taxes were mistakenly withheld from your pay, you must claim a refund by filing a non-resident Wisconsin tax return, on which you allocate ZERO income to Wisconsin. This will result in Wisconsin refunding the incorrectly withheld taxes to you.
To stop the incorrect withholding, file Wisconsin Form W-220 with your employer. A link was posted earlier in this thread.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
