State guidesEIN National Filing
Applying for an EIN in Illinois
The application, your business details, and the state registrations to check.
GUIDES FOR YOUR BUSINESSREAD & REFERENCE
Before you start, gather your entity and responsible party information. This guide separates the federal EIN application from state registrations and other business paperwork.
Why Choose Illinois for Your Business?
Economic Advantages
- 5th largest state economy ($1.0 trillion GDP)
- Chicago: 3rd largest U.S. city and global financial center
- Central U.S. location with superior transportation networks
- 36 Fortune 500 company headquarters
Business Environment
- World's busiest airports (O'Hare, Midway)
- Major rail hub and interstate highway system
- Highly educated workforce from top universities
- Diverse economy reduces market risk
Illinois Economic Highlights
36
Fortune 500 Companies
$1.0T
Annual GDP
6.2M
Workforce
#3
Largest U.S. City
Illinois EIN Requirements
Mandatory EIN Requirements
All Illinois businesses in these categories must obtain an EIN:
- •Corporations (C-Corp and S-Corp)
- •Partnerships and Multi-member LLCs
- •Any business with employees
- •Single-member LLCs (highly recommended)
- •Nonprofit organizations
- •Trusts and estates
Illinois-Specific Considerations
- IL Business Tax Registration: Illinois requires separate state tax ID registration with Illinois Department of Revenue (use federal EIN)
- Chicago Business License: Chicago requires separate business license using your EIN
- Corporate Income Tax: Illinois has 9.5% corporate income tax (7.0% base + 2.5% replacement tax) requiring proper EIN
- State Employer Registration: EIN required for IL unemployment insurance and withholding tax registration
- Sales Tax: Illinois requires EIN for Retailer's Occupation Tax registration