I live in Illinois but work in Wisconsin. Why do I have to file a Wisconsin state return? Do I need to split my salary between the 2 states?

[ditkalabowski]

I'm confused about how to split my salary between Illinois & Wisconsin.  I did not pay any Wisconsin state income tax.

[TomD8 · Accepted solution]

If you were a resident of Illinois for all of the tax year, and your Wisconsin income consists solely of W-2 wages or salary, you don't have to file a Wisconsin return.  Illinois and Wisconsin have tax reciprocity.  That means that you only have to file a tax return in your state of residence. For tax purposes, your WI earnings are considered IL income, and all your income is taxable by Illinois.  In the Personal Info section, you would answer No to the question about earning income in another state.  Note that reciprocity applies only to W-2 wages, not to any other kind of income.

Exception: if your employer mistakenly withheld WI taxes, you'd have to file a non-resident Wisconsin return in order to get those taxes refunded.

If you're an Illinois resident newly working in Wisconsin, you should file Wisconsin Form W-220 with your employer.  Here's a link to that form:  https://www.revenue.wi.gov/DORForms/w-220.pdf

[vanidosa27]

When I file the NR WI return it only gives me a $500 refund and the state of IL says I owe $1000 because the employer took out WI taxes on my income when I live in IL. How do I fix this?