What forms to use and how to calculate penalty for late filing filing IL state taxes for 2021

[esarnc]

I am querying on behalf my son who is realizing that he did not file the IL state tax return for 2021. He is a resident of NC but temporarily worked in IL from Dec 2021 through Jan 2022. He received a 1099-NEC from the IL employer for 2021 and entered that info into TT when he filed his 2021 Federal tax return but forgot to file IL state tax return for 2021 (but he filed NC state tax return where he was a resident from Jan-Nov 2021). Now he realizes that he should have filed L state tax return in 2021. He is preparing the 2021  IL state tax return using TT and it shows that he owes $148 taxes in 2021 for IL. 

1. In addition to 2021 IL-1040, are there any additional forms he should attach for the late filing and payment?2. Can he use the IL-2220 to calculate the penalty (the form says for penalties for late installment payments)?

Thank you for the experts' feedback

[HelenC12 · Accepted solution]

Per IL Department of Revenue 2022 IL -2220 Instructions:

• No, you do not need to complete this form if you owe penalties. We encourage you to let us figure your penalties and send you a bill instead of completing and filing this form yourself. If you let us figure your penalties, complete your return as usual and do not attach Form IL-2220.