Illinois: corporate income tax, franchise tax unconfirmed and an annual report due in your anniversary month.
Each fact below cites the agency page we read and the day we read it. Where a rule is still being confirmed, the page says so instead of showing a zero.
Verified facts
Corporate income tax
Yes
9.5%
Franchise or privilege
Not verified
The form (revised February 2026) confirms the franchise tax was still being collected for the 2025-and-after filing periods; the 2019 repeal schedule was not in effect on the retrieved form.
Not verifiedEntity annual report
Yes
annual · Delivered to the Secretary of State within the 60 days immediately preceding the first day of the anniversary month (or the corporation's extended filing month); $75 filing fee; minimum total due $75
Return due date
Published rule
15th day of the fourth month after the tax year end (April 15 for a December 31 year end)
Extension
Not verified
Not verifiedZero activity / minimum tax
25
The $25 minimum is the franchise tax computation minimum on the annual report (Form BCA 14.05), not an income tax minimum; the $10,000 exemption can reduce the franchise tax to zero, but the $75…
Long-form guide in professional review
Dates, extensions and payments
Filing and payment dates stay separate wherever the source supports it.
- Filing
Return filing
15th day of the fourth month after the tax year end (April 15 for a December 31 year end)
15th day of the fourth month after year end for any year end other than June 30; 15th day of the third month for a June 30 year end; 15th day of the ninth month for cooperatives
- Entity report
Entity report
annualDelivered to the Secretary of State within the 60 days immediately preceding the first day of the anniversary month (or the corporation's extended filing month); $75 filing fee; minimum total due $75
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Frequently asked questions
Does Illinois impose a corporate income tax?
Yes. 9.5%
When is the Illinois corporate return due?
15th day of the fourth month after the tax year end (April 15 for a December 31 year end)
Does an extension also postpone the tax payment?
No. The extension moves the filing date, not the payment date; unpaid tax can accrue penalty and interest.
Related states
Chosen because their corporate filing profile matches this one.
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