Form IL-1040 at a glance
What it is: The Illinois Department of Revenue 2025 Form IL-1040 is the Individual Income Tax Return.
Where and when to file: Refer to the 2025 IL-1040 Instructions for the address to mail your return.
A filled-in Form IL-1040 example: a single resident who owes tax
How to fill out Form IL-1040, box by box
Step 1: Personal Information
Enter personal information and Social Security numbers (SSN). You must provide the entire SSN(s), no partial SSN.
Enter the Mailing address (See inst. if foreign address) and Apartment number.
If not U.S., enter the Foreign nation (do not abbreviate), and enter the Email address.
Enter the County (Illinois only).
Filing status
Filing status: Single, Married filing jointly, Married filing separately, Widowed, Head of household.
Check If someone can claim you as a dependent
Check if someone can claim you, or your spouse if filing jointly, as a dependent. See instructions. You or Spouse.
Nonresident and Part-year resident
Check the box if this applies to you during 2025: Nonresident, Attach Sch. NR; Part-year resident, Attach Sch. NR.
Step 2: Income
Whole dollars only.
Line 1: Federal adjusted gross income from your federal Form 1040 or 1040-SR, Line 11a.
Line 2: Federally tax-exempt interest and dividend income from your federal Form 1040 or 1040-SR, Line 2a.
Line 3: Other additions. Attach Sch. M.
Line 4: Total income. Add Lines 1 through 3.
Step 3: Base Income
Line 5: Social Security benefits and certain retirement plan income if included in Line 1 (Generally on fed. Forms 1040/1040-SR, Lines 4b, 5b, and 6b). Attach fed. Form 1040/1040-SR.
Line 6: Illinois Income Tax overpayment included in federal Form 1040 or 1040-SR, Schedule 1, Ln. 1.
Line 7: Other subtractions. Attach Sch. M.
Line 8: Add Lines 5, 6, and 7. This is the total of your subtractions.
Line 9: Illinois base income. Subtract Line 8 from Line 4.
Step 4: Exemptions
See instructions for income limitations.
Line 10a: Enter the exemption amount for yourself and your spouse. See instructions.
Line 10b: Check if 65 or older: You + Spouse, # of checkboxes x $1,000 (checked October 20, 2026).
Line 10c: Check if legally blind: You + Spouse, # of checkboxes x $1,000 (checked October 20, 2026).
Line 10d: If you are claiming dependents, enter the amount from Schedule IL-E/EITC, Step 2, Line 1. Attach Sch. IL-E/EITC.
Line 10: Exemption allowance. Add Lines 10a through 10d.
Step 5: Net Income and Tax
Line 11: Residents: Net income: Subtract Line 10 from Line 9. Nonresidents and part-year residents: Enter the Illinois net income from Schedule NR. Attach Sch. NR.
Line 12: Residents: Multiply Line 11 by 4.95% (.0495). Cannot be less than zero. Nonresidents and part-year residents: Enter the tax from Schedule NR.
Line 13: Recapture of investment tax credits. Attach Sch. 4255.
Line 14: Income tax. Add Lines 12 and 13. Cannot be less than zero.
Step 6: Tax After Nonrefundable Credits
Line 15: Income tax paid to another state while an Illinois resident. Attach Sch. CR.
Line 16: Property tax, K-12 education expense, and volunteer emergency worker credit amount from Schedule ICR. Attach Sch. ICR.
Line 17: Credit amount from Schedule 1299-C. Attach Sch. 1299-C.
Line 18: Add Lines 15, 16, and 17. This is the total of your credits. Cannot exceed the tax amount on Line 14.
Line 19: Tax after nonrefundable credits. Subtract Line 18 from Line 14.
Step 7: Other Taxes
Line 20: Household employment tax. See instructions.
Line 21: Use tax on internet, mail order, or other out-of-state purchases from UT Worksheet or UT Table in the instructions. Do not leave blank.
Line 22: Compassionate Use of Medical Cannabis Program Act and sale of assets by gaming licensee surcharges.
Line 23: Total Tax. Add Lines 19, 20, 21, and 22.
Step 8: Payments and Refundable Credit
Line 24: Total tax from Page 1, Line 23.
Step 8: Payments and Refundable Credit, Line 25: Illinois Income Tax withheld. Attach Sch. IL-WIT.
Line 26: Estimated payments from Forms IL-1040-ES and IL-505-I, including any overpayment applied from a prior year return.
Line 27: Pass-through withholding. Attach Sch. K-1-P or Sch. K-1-T.
Line 28: Pass-through entity tax credit. Attach Sch. K-1-P or Sch. K-1-T.
Line 29: Earned Income Tax credit from Sch. IL-E/EITC, Step 4, Line 9. Attach Sch. IL-E/EITC.
Line 30: Child Tax credit from Sch. IL-E/EITC, Step 5, Line 12. Attach Sch. IL-E/EITC.
Line 31: Total payments and refundable credit. Add Lines 25 through 30.
Step 9: Total
Step 9: Total, Line 32: If Line 31 is greater than Line 24, subtract Line 24 from Line 31.
Line 33: If Line 24 is greater than Line 31, subtract Line 31 from Line 24.
Step 10: Underpayment of Estimated Tax Penalty and Donations
Step 10: Underpayment of Estimated Tax Penalty and Donations, Line 34: Late-payment penalty for underpayment of estimated tax.
Check if at least two-thirds of your federal gross income is from farming. Check if you or your spouse are 65 or older and permanently living in a nursing home. Check if your income was not received evenly during the year and you annualized your income on Form IL-2210. Attach Form IL-2210. Check if you were not required to file an Illinois Individual Income Tax return in the previous tax year.
Line 35: Voluntary charitable donations. Attach Sch. G.
Line 36: Total penalty and donations. Add Lines 34 and 35.
Step 11: Refund or Amount you owe
Step 11: Refund or Amount you owe, Line 37: If you have an amount on Line 32 and this amount is greater than Line 36, subtract Line 36 from Line 32. This is your overpayment. Otherwise, go to Line 41.
Line 38: Amount from Line 37 you want refunded to you. Check one box on Line 39. See instructions.
Line 39: I choose to receive my refund by a direct deposit, Complete the information below if you check this box: Routing number, Checking or Savings, Account number. b paper check.
Line 40: Amount to be credited forward. Subtract Line 38 from Line 37. See instructions.
Line 41: If you have an amount on Line 33, add Lines 33 and 36. If you have an amount on Line 32, and this amount is less than Line 36, subtract Line 32 from Line 36. If Lines 32 and 33 are blank (zero), enter the amount from Line 36. This is the amount you owe. See instructions.
Step 12: Health Insurance Checkbox and Signature
Step 12: Health Insurance Checkbox and Signature, Line 42: Check this box and include your email address in Step 1 if IDOR may share your income and other information from this return with the Department of Insurance in order to determine your eligibility for affordable health insurance coverage through Get Covered Illinois, the state's Health Insurance Marketplace. See instructions. Tell who in your household needs health insurance: Self, Spouse, Dependent(s).
Signature: If this is a joint return, both you and your spouse must sign. Under penalties of perjury, I state that I have examined this return, and to the best of my knowledge, it is true, correct, and complete.
Common questions about Form IL-1040
What is the IL-1040 form?
The Illinois Department of Revenue 2025 Form IL-1040 is the Individual Income Tax Return. This form is authorized as outlined under the Illinois Income Tax Act.
What to include when mailing an Illinois tax return?
Staple your check and IL-1040-V. Staple W-2 and 1099 forms here.
Where do I file it?
Refer to the 2025 IL-1040 Instructions for the address to mail your return.
Is there a penalty?
Disclosure of this information is required, and failure to provide information could result in a penalty.
Sources
[1] Form IL-1040 (R-12/25), Individual Income Tax Return, Illinois Department of Revenue (the Official source link on this page).