Illinois
Illinois business compliance calendar
What Illinois asks of a company or a nonprofit registered or doing business there, beyond the federal filings every organization owes. Pick your entity type for the full calendar with dates.
LLC 2026LLC 2027C corporation 2026C corporation 2027S corporation 2026S corporation 2027partnership 2026partnership 2027sole proprietorship 2026sole proprietorship 2027nonprofit 2026nonprofit 2027
Registration and franchise filings
| Entity | Filing | Fee | If missed |
|---|---|---|---|
| Corporations | Annual report and franchise tax, before the first day of the anniversary month of its formation, with the Illinois Secretary of State | $75 plus franchise tax on paid in capital | 10% of the delinquent franchise tax plus 2% interest a month; administrative dissolution after continued failure |
| LLCs | Annual report, before the first day of the anniversary month of its formation, with the Illinois Secretary of State | $75 | $100 late penalty; administrative dissolution after continued failure |
| Partnerships | Annual report, before the first day of the anniversary month of its formation, with the Illinois Secretary of State | $75 | $100 late penalty; administrative dissolution after continued failure |
| Nonprofits | Annual report, before the first day of the anniversary month of its formation, with the Illinois Secretary of State | $10 | $3 late penalty; administrative dissolution after continued failure |
Taxes and employers
- Corporate income tax
- Yes. C corporations file a Illinois return by the 15th day of the fourth month after the year ends, with the Illinois Department of Revenue.
- Personal income tax
- Yes. S corporations and partnerships file a Illinois information return, and employers withhold state income tax.
- Employers
- Register for unemployment insurance and file wage reports every quarter. Reconcile income tax withholding after year end.
- Sources
- Illinois Secretary of State, Illinois Department of Revenue
All Illinois rules in the pack
- Illinois annual report and franchise taxbefore the first day of the anniversary month of its formation
- Illinois annual reportbefore the first day of the anniversary month of its formation
- Illinois annual reportbefore the first day of the anniversary month of its formation
- Illinois nonprofit annual reportbefore the first day of the anniversary month of its formation
- Illinois charitable organization annual reportby the last day of the 6th month after the fiscal year ends (the last day of June for a calendar year)
- Illinois corporate income tax returnby the 15th day of the 4th month after the fiscal year ends (April 15 for a calendar year)
- Illinois corporate estimated tax paymenton the 15th day of the 4th, 6th, 9th, 12th months of the fiscal year (April 15, June 15, September 15, December 15 for a calendar year)
- Illinois S corporation returnby the 15th day of the 3rd month after the fiscal year ends (March 15 for a calendar year)
- Illinois partnership returnby the 15th day of the 4th month after the fiscal year ends (April 15 for a calendar year)
- Illinois personal income tax return with business incomeby April 15 each year
- Illinois unemployment insurance wage reportby the last day of the 1st month after each quarter
- Illinois W-2 filing with the Department of Revenueby January 31 each year
- Illinois harassment prevention trainingby January 31 each year
- Illinois retirement savings mandate (Illinois Secure Choice, 5 or more employees)with no fixed date
- Illinois sales tax returnby the 20th day of the 1st month after each quarter