Client lives in Indiana and works in Indiana, but her W2 is from the headquarters in Illinois

[Vols3827]

Do I need to fill out an Ilinois state return for her if her company W2 address is Illinois even though she works in Indiana (and lives in Indiana)?

[dd4vols]

look in boxes 15-20.... that's where state wages, state WH, etc are noted.   Use that to determine what state return you need to prepare

[IRonMaN]

At least the headquarters is only in Illinois.  Just think of the extra work involved if the headquarters was in Indonesia. 

[Skylane]

If they took out Illinois withholdings, it might not be a bad idea... Indiana may not like crediting withholdings paid to another jurisdiction.  

there are a lot of people working remotely these days but being paid as if they were commuting. You have to follow the W2 or try to get the employer to change it (good luck with that).