IL-1040: Individual Income Tax Return (2025)
Illinois · Illinois DOR · Used for tax years 2025
Form IL-1040 is the 2025 Illinois Individual Income Tax Return. It reports your 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. The Illinois return uses federal income amounts from that form. It also provides a place to staple W-2 and 1099 forms.
Attach these documents when they apply:
- Federal Form 1040 or 1040-SR: for the Social Security and certain retirement income subtraction on Line 5.
- Schedule M: for other additions or subtractions.
- Schedule IL-E/EITC: for dependent exemptions, the Earned Income Tax credit, or the Child Tax credit.
- Schedule NR: if you are a nonresident or part-year resident.
- Schedule 4255: for recapture of investment tax 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.
- Schedule 1299-C: for the credit reported on Line 17.
- Schedule IL-WIT: for Illinois Income Tax withheld.
- Schedule K-1-P or K-1-T: for pass-through withholding or the pass-through entity tax credit.
- Form IL-2210: if you check the box stating that your income was not received evenly during the year and you annualized your income on that form.
- Schedule G: for voluntary charitable donations.
How to file
For mailing, the form directs you to the 2025 IL-1040 Instructions for the return address. Those instructions are not included here, and the form itself does not print a mailing address or provide e-filing directions.
The form provides designated places to staple your W-2 and 1099 forms and your check with Form IL-1040-V. Sign the return in Step 12. If filing jointly, both you and your spouse must sign.
Common mistakes
- Entering only part of a Social Security number: the form requires the entire SSN for each person listed, not a partial number.
- Including cents: enter amounts in whole dollars only.
- Leaving Line 21 blank: the form explicitly says not to leave the use tax line blank.
- Overstating nonrefundable credits: the total on Line 18 cannot exceed the tax on Line 14.
- Missing a spouse’s signature: both spouses must sign a joint return.
- Not completing the refund choice: check one box on Line 39. If you choose direct deposit, complete the routing number, account number, and checking or savings selection.
Questions people ask
What tax rate does the form use for Illinois residents?
Residents multiply the net income on Line 11 by 4.95% (.0495) to calculate Line 12. The result cannot be less than zero.
What do nonresidents and part-year residents enter for net income and tax?
They enter Illinois net income from Schedule NR on Line 11 and tax from Schedule NR on Line 12. Schedule NR must be attached.
How can I receive my refund?
Line 39 offers direct deposit or a paper check. For direct deposit, provide your routing number and account number and select checking or savings. Line 40 also allows you to designate an amount to be credited forward.
What does the health insurance checkbox do?
Checking Line 42 allows IDOR to share income and other information from your return with the Department of Insurance to determine eligibility for affordable coverage through Get Covered Illinois. Include your email address in Step 1 and indicate whether you, your spouse, or your dependents need health insurance.