View up to date information on how Illinois is handling the Coronavirus Disease 2019 (COVID-19) from the
State of Illinois Coronavirus Response Site
You may be assessed a late-payment penalty for underpayment of estimated tax if you were required to make estimated tax payments and failed to do so, or failed to pay the required amount by the payment due date. See Form
IL-1040-ES, Estimated Income Tax Payments for Individuals, for more information.
If you have additional inquiries, you may submit them to the Questions, Comments, or Request form.