Illinois Personal Tax Extension 2026: 2025 Tax-Year Filing Guide
Individual Income Tax · Form IL-1040
Illinois generally grants an automatic extension for individual returns. Illinois generally provides an automatic six-month filing extension. For federal details, see our federal tax extension resources.
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✓ Secure e-filing✓ 24/7 filingIllinois generally grants an automatic extension for individual returns. Illinois generally provides an automatic six-month filing extension.
Last updated: September 12, 2026Illinois Personal Tax Extension: Filing Details
Illinois generally grants an automatic extension for individual returns. Illinois generally provides an automatic six-month filing extension.
Quick Reference: Deadlines and Forms
Use this summary to confirm Illinois filing deadlines, forms, and payment requirements.
| Item | Illinois personal return | Deadline or method |
|---|---|---|
| Original deadline | Form IL-1040 | April 15, 2026 |
| Extended deadline | Automatic | October 15, 2026 |
| Return form | Form IL-1040 | Use the current form |
| Payment | Form IL-505-I | Due April 15, 2026 |
Frequently Asked Questions
Answers about Illinois personal tax extensions.
Yes. Illinois generally provides an automatic six-month extension to file the individual return.
Use Form IL-1040 for the Illinois individual income tax return.
Pay any expected balance by April 15; the extension does not extend the payment deadline.
Check the Illinois Revenue for current forms and instructions.