IL-1040-X: Amended Individual Income Tax Return (2024)
Illinois · Illinois DOR · Used for tax years 2024
Form IL-1040-X is the 2024 Illinois Amended Individual Income Tax Return. It reports corrected income, exemptions, taxes, credits, and payments to calculate an adjusted refund or amount owed.
Who files this form
Use the 2024 Form IL-1040-X to amend a previously filed Illinois individual income tax return for tax year 2024. The form lists federal changes, accepted net operating loss (NOL) changes, and state changes as reasons for amending.
If a change to your federal return resulted in an overpayment, do not file this form until you receive notification that the IRS accepted the changes.
What you'll need
Gather the records and attachments that apply to your changes:
- Your original Form IL-1040 or latest Form IL-1040-X, including its filing date, and records of payments and any overpayment adjusted by the Department.
- Your federal Form 1040 or 1040-SR for federal income figures. Attach it when reporting the Social Security benefits and retirement income subtraction on Line 5. Attach federal Schedule 1 for the subtraction on Line 6.
- A copy of federal Form 1040X or Form 1045 if you filed one.
- A copy of your federal finalization for a federal change or accepted NOL change.
- W-2 and 1099 forms, plus Schedule IL-WIT for Illinois income tax withheld.
Attach the applicable Illinois schedules:
- Schedule M for other additions or subtractions.
- Schedule IL-E/EITC for dependents, the Earned Income Tax credit, or the Child Tax credit.
- Schedule NR for nonresidents and part-year residents.
- Schedule 4255 for investment tax credit recapture.
- Schedule CR for income tax paid to another state while an Illinois resident.
- Schedule ICR for property tax, K-12 education expense, and volunteer emergency worker credits.
- Schedule 1299-C for the credit reported on Line 17.
- Schedule K-1-P or K-1-T for pass-through withholding or the pass-through entity tax credit.
The form refers you to the 2024 IL-1040-X Instructions for required attachments. Those instructions were not provided here.
How to file
Enter your personal information and corrected figures. In Step 11, identify the reason for the amendment, give the filing date of your original or latest amended return, and explain your changes in detail. Attach a separate sheet if needed.
Sign and date the return. For a joint return, both spouses must sign.
The form directs you to the 2024 IL-1040-X Instructions for the mailing address. No mailing address or e-file directions are provided in the supplied text.
Use the marked areas to staple your W-2 and 1099 forms and, if paying by check, your check and Form IL-1040-X-V.
Common mistakes
- Filing before IRS acceptance: If your federal change resulted in an overpayment, wait for notification that the IRS accepted it.
- Entering partial Social Security numbers: Provide the entire number for each person listed.
- Changing use tax: Line 21 must keep the use tax amount reported on your original return.
- Including interest on Line 35: Do not include interest you received in the original or Department-adjusted overpayment amount.
- Exceeding the credit limit: Total credits on Line 18 cannot exceed the tax on Line 14.
- Missing a spouse’s signature: Both spouses must sign a joint return.
- Skipping required information: The form warns that failure to provide information could result in a penalty.
Questions people ask
Can I receive my refund by direct deposit?
Yes. On Line 37, choose direct deposit and enter your routing number, account number, and whether the account is checking or savings. You may choose a paper check instead.
Can I apply some of my overpayment to estimated tax?
Yes. Line 38 subtracts the amount you want refunded on Line 37 from your overpayment on Line 36. The remainder is applied to estimated tax.
Do I need to attach my federal amended return?
If you filed federal Form 1040X or Form 1045, Step 11 requires you to attach a copy.
What if my name, address, or Social Security number changed?
Check the box in Step 1, item B, if the information listed differs from your previously filed return.
Where do I explain my changes?
Use Step 11, item D, to explain your reasons in detail. Attach a separate sheet if you need more room.