Filing an Amended Individual Income Tax Return

Did you make an error or forget to report information on your tax return?

If you find yourself in this situation, you must file an amended income tax return.

How do I file an amended return?

File Form IL-1040-X, Amended Individual Income Tax Return, if

• you discover that you made an error on your Illinois return after it was filed, or
• your federal return has been adjusted either by the Internal Revenue Service (IRS) or on a 1040X, Amended U.S. Individual Income Tax Return, you filed; the change affects your Illinois income, additions, subtractions, exemptions, or credits; and the change is final.

Note: If the federal change results in a refund, do not file Form IL-1040-X until you receive notification that your change has been accepted by the IRS.

What if I need tax assistance?

If you have any last minute questions about your IL-1040 Individual Income Tax Return, or other tax-related topics, give us a call. Our staff will be available until 7:00 PM tonight.

• 1 800 732-8866 or 217 782-3336
• 1 800 544-5304 TTY

Over-the-phone translation services are available.

Resources

For the most up-to-date information, printable forms, schedules, and instructions for the 2023 tax year, please visit IDOR’s website at: tax.illinois.gov.