How To File An Income Tax Return Extension In Illinois

File taxes in the state of Illinois.

The first question is, “do you need to file an extension”? The answer is yes if ALL of the follow apply to you:

  1. You can not file on time (4/15)
  2. You owe a tax
  3. You pay using a check or money order, not electronic funds transfer

Good news, the Illinois Department of Revenue (IDR) grants you a 6-month automatic extension. That means you don’t need to file your tax return with the IDR up to October 15th. It’s automatic, which means you don’t need to file anything to receive the extension. For taxpayers that need more than 6 months, the IDR will grant you an extension greater than 6 months IF the IRS grants you an extension.

This does not mean you receive an automatic extension for filing your federal Income Tax Return with the Internal Revenue Service (IRS). To file an extension with the IRS, you can request an extension of time by:

  1. Paying all or part of your estimated income tax due and indicate the payment is for an extension using Direct Pay or a Credit Card.
  2. File Form 4868 electronically by using the IRS e-file system on line or with the help of a tax professional.
  3. Filing a paper Form 4868 and enclosing payment of your estimated tax due (optional).

Although the IDR extension is automatic, you may owe penalties and interest on any unpaid taxes beginning on the date the tax was originally due. You may also owe penalties and interest to the IRS even if you file an extension. Filing late does not mean you can pay late.

In the State of Illinois, if you owe a tax and you don’t use electronic funds for payment, you need to file Form IL-505-I.

Do you owe penalties and interest?  Yes if you:

  1. File your return with the IDR later than the extension due date – Penalty
  2. Bounce a check to the IDR – Penalty
  3. Pay your taxes past the original due date- Penalty
  4. Pay your taxes past the original due date – Interest

Need additional help? Call the Illinois DOR at (800) 732-8866. Do you need a professional to help file your Illinois tax return, federal tax return or both? will help you find a verified Tax Professional in about 4 minutes. Tax Professionals charge for their services however will find you a Certified Public Accountant, Enrolled Agent or Tax Attorney at no cost. & connect taxpayers with verified local tax and accounting professionals.  Learn more at or