Doesn't the Illinois notice say how to contest those findings? basically you would need documents to show Illinois you were a part-year resident.
To prove residency in Illinois, you need to provide at least two proofs of residency1. Examples of documents that can be used to prove residency include:
- Wisconsin tax return or federal tax transcript
- Wisconsin driver’s license
- Utility or rent bills for Wisconsin
- Wisconsin auto registration card
- Residential lease in the applicant’s name
- Corrected Wage and tax statements (IRS Form W-2c showing the breakdown between WI and Il wages
