Not sure what proof you thought you needed in order to file your IL tax returns. IL is pretty picky when it comes to e-filing and will not allow you to e-file an IL return without an IL driver's license or state ID, but that did not prevent you from preparing and filing those returns by mail.
If you are getting a refund for the state return there will not be a penalty for filing late; if you owe tax to IL you will now owe with penalties and interest, for which the state will bill you.
You are too late to e-file a past year IL return; a 2023 IL return can still be e-filed if you successfully e-filed a 2023 federal return. If you used TT to prepare your past year federal return you can use the CD/download software to prepare the past year IL return---it will require using a full PC or Mac, not a mobile device. Or you can get the forms from the state website and prepare them by hand to mail in.
I think someone should have told me --IL different than 4 other states I have lived in...First time in 40 years of returns--I have an issue. FIRST YEAR residents, have some weird STATE rule and didn't know about issue for 3 years!!! I need my refund(s)and somehow I supposedly need PROOF from 4 YEARS ago,I was only in IL for 3 months. I feel cheated from this site and IL State---IMHO
@Nonames2025 Your issue is not at all clear. What happened with IL? Do you still live in IL or did you only live (or work) in IL for a short time? Your post is confusing. Put aside whatever you are mad about and provide the facts.
Its very convoluted and if 3 tax guys, couldn't explain it to me-I should DEFINETLY not expect someone online to be able to understand-----venting, as I said 40 years-no issues.
Bottom line, IL State wants me to prove I DIDNT live here for more than 3 months in 2021-----thanks for being abrupt and will continue to get more clarification before I post again! I have lived here since 2021.