Turbotax may allow e-filing of IL-1040-X, IL does not. there are required documents that must be included and they can not be included if you were to efile
What must I attach to my Form IL-1040-X?
If you are filing Form IL-1040-X because:
A) you filed a federal Form 1040X to report a federal change other
than an NOL carryback, you must include a copy of that form and
proof of federal finalization.
If your federal change resulted in an overpayment, proof of federal
finalization includes a copy of the notification you received from
the IRS stating that they accepted the changes shown on your
federal Form 1040X; e.g., a refund check, “Statement of Account,”
agreement, or judgment.
If your federal change resulted in a balance due, proof of federal
finalization includes a copy of your federal Form 1040X and a
copy of the check you sent to the IRS to pay the tax due.
If you do not have a copy of this notification, please contact the
IRS to request a tax account transcript.
B) of a change made by the IRS, you must include copies of all the
federal examining officer’s reports, including preliminary, revised,
corrected, and superseding reports.
C) of any other changes, see the instructions for Form IL-1040 and
any schedules to see what to attach.
If the change you are making requires a supporting
schedule or form, you must attach it to your Form IL-1040-X.
Without proper attachments, IL may partially or totally deny your claim.
Mail your return to:
ILLINOIS DEPARTMENT OF REVENUE
PO BOX 19047
SPRINGFIELD IL 62794-9047
actually, an e-file IL-1040-X should be rejected
