IL-1040: Individual Income Tax Return (2024)
Illinois · Illinois DOR · Used for tax years 2024
Form IL-1040 is the 2024 Illinois Individual Income Tax Return. It reports income, exemptions, taxes, credits, and payments to calculate your refund or the amount you owe.
What you'll need
Have your federal Form 1040 or 1040-SR available for the income amounts requested on the return. Attach it if you claim the Social Security and retirement income subtraction on Line 5.
Depending on the items you report, the form also calls for:
- Withholding: W-2 and 1099 forms, plus Schedule IL-WIT for Illinois income tax withheld.
- Estimated payments: Payment amounts from Forms IL-1040-ES and IL-505-I, including any prior-year overpayment applied.
- Nonresident or part-year resident income: Schedule NR.
- Other additions or subtractions: Schedule M.
- Dependents, Earned Income Tax Credit, or Child Tax Credit: Schedule IL-E/EITC.
- Other credits: 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; or Schedule 1299-C.
- Pass-through withholding or entity tax credit: Schedule K-1-P or K-1-T.
- Other applicable items: Schedule 4255 for investment tax credit recapture, Schedule G for charitable donations, and Form IL-2210 if you annualized your income and check Line 34c.
For direct deposit, have your routing number, account number, and checking or savings account type ready.
How to file
- Complete your personal information, income, tax, credits, payments, and refund or amount owed. Use whole dollars only.
- Attach the schedules required for the amounts you report. The front of the form marks where to staple W-2 and 1099 forms and where to staple your check and Form IL-1040-V.
- Sign and date the return. For a joint return, both spouses must sign.
- Mailing: The form directs you to the 2024 IL-1040 Instructions for the mailing address. Those instructions were not provided, so no mailing address is available in the supplied text.
Common mistakes
- Entering only part of a Social Security number: The form requires the entire number for each person listed.
- Including cents: Use whole dollars only.
- Leaving Line 21 blank: The form specifically says not to leave the use tax line blank.
- Missing a spouse’s signature: Both spouses must sign a joint return.
- Claiming credits above the stated limit: Total nonrefundable credits on Line 18 cannot exceed the tax on Line 14.
- Entering negative tax: Lines 12 and 14 cannot be less than zero.
- Leaving refund instructions incomplete: Check one refund method on Line 39. If choosing direct deposit, complete the bank information.
Questions people ask
What tax rate does the form use for Illinois residents?
Residents multiply the net income on Line 11 by 4.95% to calculate Line 12. The result cannot be less than zero.
What do nonresidents and part-year residents enter for income and tax?
They enter Illinois net income and tax from Schedule NR on Lines 11 and 12 and attach Schedule NR. They also check the applicable residency box in Step 1.
How can I receive my refund?
Line 39 offers direct deposit or a paper check. For direct deposit, enter your routing and account numbers and select checking or savings.
Can I apply part of my overpayment forward instead of receiving it as a refund?
Yes. Line 38 is the amount you want refunded. Line 40 is the amount to be credited forward, calculated by subtracting Line 38 from Line 37.
What does the health insurance checkbox do?
Checking Line 42 allows IDOR to share your income information with other Illinois state agencies to determine your eligibility for health insurance benefits. The form also tells you to include your email address in Step 1.