Illinois I Business State Tax Extension I Fiduciaries

• Illinois grants your business an automatic 6-month extension provided you have obtained an approved IRS extension.
• The extension is NOT an extension to pay any taxes you may have due.
• Tax payments are due by the original return due date.

Illinois Department of Revenue
P.O. Box 19053
Springfield, IL 62794-9053

Late filing:

• Lesser of $250 or 2% of tax liability, reduced by timely payments or credits.

Nonfiling:

• Greater of $250 or 2% of tax liability up to $5,000, if a return is not filed within 30 days after receiving a notice of nonfiling.

Before audit:

• 2% of tax liability for payments 1-30 days late.
• 10% of tax liability for payments 31 or more days late.

After audit initiation:

• 15% of tax liability if paid within 30 days after issuance of the audit-prepared amended return or waiver of restrictions on assessment.
• 20% of tax liability if taxpayer:
• paid after the expiration of the 30-day period;
• paid under protest; or
• claims a credit or refund for tax, penalties, or interest determined due upon audit.