Illinois . 2026 filing guide
Illinois Secretary of State filings, deadlines, and how to do them right.
Annual reports, business search, registered agent changes, reinstatement, dissolution, tax registration. Every Illinois filing explained, plus the business environment, regulatory bodies, and a year-round compliance calendar. Verified against the Illinois Secretary of State, Department of Business Services as of June 2026.
Verified against Illinois Secretary of State, Department of Business Services on Jun 12, 2026
Agency
Illinois Secretary of State, Department of Business Services
Branded as Illinois Business Services
Phone
217-782-6961
Mon-Fri 8am-4:30pm CT
Annual due
Anniversary month
$300 late fee
Processing
7-10 business days
Online filings
Illinois business environment
Why founders choose Illinois (and what to know first)
Chicago is the largest Midwest business hub. Major Fortune 500 concentration (Boeing, McDonald's, Caterpillar). Flat 4.95% income tax simplifies planning. Strong logistics infrastructure.
Economy
~$1T economy
Registered entities
~1.6 million active entities
New formations / year
~200,000 annually
Key industries
Manufacturing, agriculture, finance (Chicago), transportation (O'Hare hub), technology, healthcare