I am not confused. Someone I know got audited for this same issue. I will link the comment to you so you can see verbatim:
"Not true. I just went through this. IL Department of Revenue is going to send you mail audit asking for your employer to provide days worked in each state. No employer will do that and therefore IL will not allow credit. Publication 302 exceptions. Also, there is a case that went through the IL court system in 2015 that allows for that double taxation scheme, so basically save yourself 10% in penalties and pay tax in both states….
W-2 doesn't show Illinois wages but I believe under Illinois law since all the work was performed in Illinois the wages should also be shown as Illinois wages. Income taxed by NY would have to be also taxed using IL income definition to be eligible for credit. As NY has convenience of the employer rule and taxes based on that and IL would not tax that income using it’s rules you will be basically double taxed and not eligible for this credit. One way out of it is for the employer to create a bonafide office for you, stop NY withholding and withhold just IL taxes. "
https://ttlc.intuit.com/community/state-taxes/discussion/re-live-in-il-but-work-for-ny-company-un[pr...
The comment is in this post.
