The State of Illinois has issued the following guidance regarding income tax filing deadlines for individuals:
- The filing deadline has been extended until May 17, 2021.
- The payment deadline is also May 17, 2021. Penalties and interest on underpayments will be calculated from that date
- Illinois "is providing for an additional option upon which taxpayers can base their 2021 estimated tax payments. Taxpayers are required to estimate their tax liability for the year and make four equal installments. Taxpayers will not be assessed a late estimated payment penalty if the amount of the timely-paid installments equals 90% of actual liability for 2021, or 100% of actual liabilities for 2019 or 2020."
- If you receive a federal extension of more than six months, you are automatically allowed that extension for Illinois. These extensions do not grant you an extension of time to pay any tax you owe. If you determine that you will owe tax, you must use Form IL-505-I, Automatic Extension Payment for Individuals, to pay any tax you owe to avoid penalty and interest on tax not paid by April 15, 2021.