INSTRUCTIONS: ILLINOIS AMENDED INDIVIDUAL INCOME TAX RETURN (Form IL-1040-X)

Those who must file an amended individual income tax return in Illinois do so with a form IL-1040-X. This document is found on the website of the Illinois Department of Revenue.

Illinois Amended Individual Income Tax Return IL-1040-X Step 1: Step 1 requires you to provide your name, mailing address and Social Security number. Those filing jointly with their spouse should provide their name and Social Security number as well. Indicate if your Social Security number has changed from your previously filed return, indicate your filing and residency status with a check mark, indicate if you are a member of a same-sex civil union with a check mark, and check the box indicating why you are filing an amended return.

Illinois Amended Individual Income Tax Return IL-1040-X Step 2: In Step 2, explain in detail the reason why you are filing an amended return. Include the date on which you filed your original IL-1040 form and indicate if you filed an amended federal return. If so, you must attach a copy.

Illinois Amended Individual Income Tax Return IL-1040-X Step 3: In Steps 3 and 4, two columns are provided. Column A requires you to enter your originally reported or last reported figures, while Column B requires you to enter the corrected figures. Document your income on lines 1 through 4.

Illinois Amended Individual Income Tax Return IL-1040-X Step 4: Calculate your base income as directed on lines 5 through 9.

Illinois Amended Individual Income Tax Return IL-1040-X Step 5: Note all exemptions being claimed on lines 10a through 10c.

Illinois Amended Individual Income Tax Return IL-1040-X Step 6: Residents should calculate their net income on line 11, while non residents should calculate their net income on line 12.

Illinois Amended Individual Income Tax Return IL-1040-X Step 7: Calculate your tax due on lines 13 through 15.

Illinois Amended Individual Income Tax Return IL-1040-X Step 8: Lines 17 through 21 concern nonrefundable credits.

Illinois Amended Individual Income Tax Return IL-1040-X Step 9: Lines 22 and 23 adjust your tax liability based on household employment tax, if applicable.

Illinois Amended Individual Income Tax Return IL-1040-X Step 10: Lines 24 through 31 concern overpayments, previously made payments and credits.

Illinois Amended Individual Income Tax Return IL-1040-X Step 11: Step 4 provides instructions to calculate the final balance or refund due.