I worked in Illinois but lived in Wisconsin. My employer deducted Illinois tax. We file married filing jointly for federal and Wisconsin. How to get refund from Illinois?

in addition to Wisconsin, you'll need to file an Illinois nonresident return. Since there's reciprocity between the two states you'll get a full refund of the Illinois taxes but be prepared to owe Wisconsin. You'll need to ask your employer to start withholding Wisconsin taxes or make estimated tax payments.  If you don't and also for 2023 you may be subject to Wisconsin underpayment penalties. 

Thanks for the reply. I am aware that i need to file IL taxes. However, on their website 'Should I file an income tax return if I live in another state but worked in Illinois?', they mention that 

• If your employer withheld Illinois tax from your pay in error, you must attach Form W-2c, Corrected Wage and Tax Statement, or a letter from your employer, on company letterhead, to your Form IL-1040 to verify that Illinois tax was withheld in error.

How do I get a W-2c from my employer since the error was mine rather than the employer's?

Is there a better way to get back IL refund than filing a W-2c?

File a Non-Resident IL return.  Be sure to prepare the IL return before the Wisconsin return.

@tsai69951 

Sure enough, I filled a non-resident IL return followed by a resident WI return on turbo-tax. However, in the final step of the return, I did not get any refund from the IL return. Also, I am not allowed to take tax credit for IL tax paid in my WI return. So how do I get refund for IL taxes paid?

Why are you not allowed to get a credit in WI for taxes paid to IL?  WI does allow for a credit of taxes paid to other states.  It will not result in a refund of the taxes paid to the other state if the other state rate is higher, but it would lower your liability for WI. 

Since you work in IL, you will have to pay taxes to IL, so it is very possible that you will not get any type of refund from IL.