IL-2210: Computation of Penalties for Individuals (2025)
Illinois · Illinois DOR · Used for tax years 2025
Illinois Form IL-2210 calculates individuals’ late-payment penalties for underpaid estimated tax and unpaid tax, as well as late-filing penalties. It is attached to Form IL-1040 and includes worksheets to figure penalties and the amount owed or overpaid.
Who files this form
Illinois Form IL-2210 is for individuals who choose to calculate their own penalties for underpayment of estimated tax, unpaid tax, or late filing.
The form encourages you to let the Illinois Department of Revenue calculate your penalties and send you a bill instead of completing it yourself. If you complete IL-2210, attach it to Form IL-1040.
When it's due
For tax year 2025, the form lists these estimated-tax installment due dates:
- Quarter 1: 15th day of the 4th month of the tax year.
- Quarter 2: 15th day of the 6th month of the tax year.
- Quarter 3: 15th day of the 9th month of the tax year.
- Quarter 4: 15th day of the 1st month after the end of the tax year.
The form refers to the return’s original and extended due dates but does not print specific calendar dates for them.
What you'll need
Have these records available to complete the applicable parts of the form:
- Your current-year Form IL-1040 and prior-year tax return, including tax and credit amounts.
- Your name and Social Security number as shown on Form IL-1040. If your prior-year return used a different Social Security number, you will also need that number.
- W-2 and 1099 forms showing Illinois withholding.
- Records of pass-through withholding made on your behalf.
- Payment amounts and dates, including estimated payments, Form IL-505-I payments, and credits carried forward from a prior year.
- If you choose to annualize income, Illinois base-income information for the first 3, 5, and 8 months and all 12 months of the year.
How to file
Attach completed Form IL-2210 to your Form IL-1040. It is identified as IL Attachment No. 19.
Enter the estimated-tax underpayment penalty from IL-2210, Line 22, on Form IL-1040, Line 34, rounded to whole dollars.
The supplied form does not give a mailing address or e-filing directions. For payment options, it refers you to the instructions for Form IL-1040, Line 41.
Common mistakes
- Using the wrong tax amount for required installments. Use the tax shown on your original return, not an amended return filed after the extended due date.
- Completing Penalty Worksheet 1 unnecessarily. Do not complete it if you paid the required amount from Line 13 by each quarter’s payment due date.
- Calculating a late-filing penalty when it does not apply. Calculate it only if you file after the extended due date and your tax was not paid by the original due date.
- Annualizing without meeting the stated conditions. Complete Step 6 only if your income was not received evenly throughout the year and you choose to annualize. Complete one column’s Lines 38 through 56 before moving to the next.
- Skipping the worksheet instructions. The form says you must follow the instructions to complete the penalty worksheets properly. Those instructions were not included in the supplied text.
Questions people ask
When is the estimated-tax underpayment penalty waived?
The department will waive it if you timely paid the lesser of 100% of the prior year’s tax liability or 90% of the current year’s tax liability. The form reflects this waiver if you calculate the penalty yourself.
What if Step 2, Line 5, is $1,000 or less?
Enter zero on Line 7 and go to Step 3. The form gives the same direction if you are not required to make estimated tax payments.
What late-payment penalty rates are printed on the form?
The rates are 2% for payments 1 through 30 days late and 10% for payments 31 or more days late.
How is the late-filing penalty calculated?
When it applies, subtract credits and payments made by the original due date from the tax total in Step 5. Multiply the result by 2%. The penalty is the lesser of that amount or $250.