I worked in Indiana and Illinois but am a full time resident of Illinois. The state return keeps adding a nonresident tax onto my Illinois state taxes. Why?

[CarolynM]

These states do not have reciprocity.

As a result, you do owe Illinois taxes on the wages you earned out of state when you are full time resident.

You will receive a credit for the taxes paid to Indiana if you complete that tax return first, but you do still owe Illinois tax on these wages.