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How to File an Illinois State Tax Amendment

Illinois State Taxes
amend Illinois taxes
Illinois
"The Prairie State"

When Do I Need to Prepare and File an Illinois Amended Tax Return?

If the change affects the tax return you filed in the state of Illinois, then you have 3 years from the original return or the extended due date, or for up to one year since the Illinois state tax was paid, whichever is latest. If the change resulted from a recalculation of federal taxes, you must file an amendment form within 2 years and 120 days of the federal finalization.

How Do I Fix My Accepted Illinois Tax Return or File a Tax Amendment for Illinois?

The state of Illinois states that a taxpayer should file a tax amendment form if there was a change in income, tax credits, or deductions. That change can come from you amending your federal tax return, or the IRS making the corrections for you, or any other sort of recalculation. Follow these instructions on how to amend an Illinois tax return: 

  1. Download and fill out Form IL-1040-X.
  2. Print out your amendment and mail it to this address: Illinois Department of Revenue, P.O. Box 19007, Springfield, IL 62794-9007.

Illinois State Tax Amendment Forms (Download, Fill Out, Print Out, and Mail)

To amend your Illinois state tax return, complete Form IL-1040-X for the year you are amending.

Form (Tax Year) Description
Form IL-1040-X (2016) Amended Individual Income Tax Return
Form IL-1040-X (2015) Amended Individual Income Tax Return
Form IL-1040-X (2014) Amended Individual Income Tax Return
Form IL-1040-X (2013) Amended Individual Income Tax Return
Form IL-1040-X (2012) Amended Individual Income Tax Return
Form IL-1040-X (2011) Amended Individual Income Tax Return

How Do I Check My Illinois Amended Tax Return Status?

You can call the Illinois Department of Revenue at 800 732-8866.

What Are the Penalties, Interest, and Fees Related to Illinois Tax Amendments?

The state of Illinois has numerous tax penalties, including a late-filing/non-filing penalty and a late payment penalty.

The late-filing penalty is 2% of the tax owed or the lesser of $250. If you received a notice about non-filing and you don't file your return within 30 days after receiving the notice, an additional penalty equal to 2% of the tax due or equal to the greater of $250 applies. This additional penalty will not go over $5,000, and it will be assessed even if there is no tax due.

The late payment penalty is based on the number of days the tax owed is submitted after the original tax return deadline:

2%: 1 - 30 days
10%: 31 days and over

Any amount that is not paid until after the initiation of an investigation or audit of your liability faces a 15% penalty.

There is also a 20% penalty of any amount that is not paid within 30 days after the submission of an audit-prepared amended return or Form IL-870 (Waiver of Restrictions) when the investigation or audit ends. This rates also applies to any amount paid within the 30-day period if you do not sign and submit the amended return within that period of time or if you paid the tax liability under protest or file a claim or refund of the payment.

Where Do I Mail My Amended Illinois Tax Return? - Illinois Mailing Address:

Illinois Department of Revenue
P.O. Box 19007
Springfield, IL 62794-9007

Illinois Department of Revenue Phone Number: 800 732-8866

Illinois Department of Revenue

Where Do I Find More Illinois State Tax Information?

How Do I Only Prepare and File an Illinois Tax Return?

Where is My Illinois State Tax Refund?

Illinois Tax Extension

Illinois State Income Taxes

What If I Need to File an Amended IRS Tax Return?

Learn how to file a federal tax amendment.