Illinois has announced that the tax filing deadline for individual returns is May 17th.
Illinois Filing Due Date: Individual income tax returns are due by April 15 — or by the 15th day of the 4th month following the end of the taxable year (for fiscal year filers).
Extended Deadline with Illinois Tax Extension: Illinois offers a 6-month extension, which moves the filing deadline from April 15 to October 15 (for calendar year filers).
Illinois Tax Extension Form: Illinois tax extensions are automatic, which means there is no application or written request to submit.
Illinois Extension Payment Requirement: An extension of time to file is not an extension of time to pay your Illinois income tax. All state tax payments are due by the original deadline of the return. Any Illinois tax not paid by the proper due date will be subject to interest and penalties. You can make an Illinois extension payment with Form IL-505-I, or pay electronically through Illinois WebPay for Individual Income Tax: www.revenue.state.il.us/webpay
Illinois Tax Extension Tips: If you have an approved Federal tax extension (IRS Form 4868), you will automatically receive an Illinois tax extension. However, if you owe Illinois tax, it must still be paid by the original due date.
NOTE: If you owe zero Illinois tax, you will be granted an automatic state extension without having to file anything.