BASIC INFORMATION
WHO (must file):
Residents
An Illinois resident taxpayer must file if
you have filed a federal income tax return
or if you were not required to file a federal
tax income return,
but your Illinois base income is greater
than your
Illinois
exemption allowance.
Nonresidents
You must filed if you earned enough taxable
income from Illinois sources to have a tax
liability
OR you want a refund of any Illinois Income
Tax withheld in error.
You must attach a letter of explanation from
your employer.
WHAT
(forms do you file)
Residents
Form IL-1040 Illinois Individual Income Tax
Returns
Nonresidents
Form IL-1040 Illinois Individual Income Tax
Return and Schedule NR
WHEN (are the tax returns due)
Original due date: April 15th
Extended due date: October 15th
WHERE (do you mail the tax returns)
If
you are expecting a refund or no payment,
send to:
Illinois Department of Revenue
Springfield, IL 62719-0001
If you are sending a payment, send to:
Illinois Department of Revenue
Springfield, IL 62726-0001
