January 22, 2026 – The Illinois Department of Revenue (IDOR) announced that it will begin accepting 2026 individual income tax returns on Monday, January 26, coinciding with the start of the federal filing season. The deadline to file Illinois returns is Wednesday, April 15, 2026.
IDOR encourages taxpayers to file electronically and choose direct deposit to receive refunds more quickly and securely. During the 2025 filing season, over 6.3 million individual returns were filed, with 91.3% submitted electronically. Taxpayers who file accurate electronic returns with direct deposit typically receive refunds in about four weeks.
The department’s free online filing system, MyTax Illinois, guides users through a simple question-and-answer process, automatically performs calculations, and reduces errors with prepopulated information. MyTax Illinois also allows users to make payments, respond to inquiries, check refund status, and access estimated payments or Form 1099-G information. Taxpayers may also file using tax software, a tax professional, or paper forms.
IDOR reminds taxpayers to review their eligibility for tax credits, including the Illinois Earned Income Tax Credit, Property Tax Credit, and K–12 Education Expense Credit, which may reduce taxes owed or increase refunds.
Changes to the U.S. Postal Service’s postmarking rules could affect mailed returns and payments. The USPS now records the date of the first automated processing rather than the drop-off date. IDOR recommends mailing returns early or requesting a manual postmark to avoid potential late penalties.
Tax assistance is available by calling 1-800-732-8866 or 217-782-3336, with free language support for limited English proficiency individuals. Updated information, forms, and instructions for the 2026 tax season are available at tax.illinois.gov
