The Illinois Department of Revenue (IDOR) announced it will begin accepting individual income tax returns for the 2026 tax year on January 26, coinciding with the opening of the federal filing season by the Internal Revenue Service. The deadline to file state returns is April 15, 2026.
IDOR recommends that taxpayers submit their returns electronically and use direct deposit for refunds. “We want the tax filing process to be as smooth and stress-free as possible,” said IDOR Director David Harris. “Before filing, you should make sure you have all income documents, such as W-2s and 1099s. Filing online, reviewing information carefully, and submitting your returns early can help avoid delays and get you any refunds you may be entitled to sooner.”
In the previous filing season, IDOR processed over 6.3 million individual income tax returns, with about 91 percent filed electronically. Those who file accurate electronic returns with direct deposit typically receive refunds in approximately four weeks.
Taxpayers are encouraged to use MyTax Illinois, a free online system provided by IDOR that guides users through filing using a question-and-answer format. The platform automatically performs calculations and uses prepopulated information when available to minimize errors. MyTax Illinois also allows users to make payments, respond to department inquiries, check refund status via Where’s My Refund?, and access other services.
Other options for filing include commercial tax software, professional preparers, or submitting paper Form IL-1040.
IDOR reminds taxpayers to review their eligibility for credits such as the Illinois Earned Income Tax Credit, Property Tax Credit, and K–12 Education Expense Credit before submitting their return. “Tax credits can put more money back in your pocket,” Harris said. “Taking time to review the credits you qualify for can make a real difference.”
A recent change by the United States Postal Service (USPS) means postmarks now show when mail was first processed rather than when it was dropped off. This could affect timely submission of tax documents sent by mail. USPS will still provide manual postmarks upon request at its offices. IDOR advises mailing returns earlier than usual or requesting a manual postmark if submitting close to the deadline. “If you plan to mail your return or payment, don’t wait until the last day,” Harris stressed. “Sending it early or requesting a manual postmark at the post office can help protect you from late penalties.”
Assistance is available from IDOR by phone at 1-800-732-8866 or 217-782-3336; language support is provided for individuals with limited English proficiency.
Current information on forms and instructions for the 2026 tax season is available at https://tax.illinois.gov/.
