How to Register for Illinois Sales Tax
Registering for an Illinois Certificate of Registration (sales tax license) is free and can be completed online through MyTax Illinois.
What You Will Need Before Starting
- Social Security Number or FEIN for all owners
- Federal Employer Identification Number (EIN)
- Business address in Illinois
- Business entity type and formation date
- NAICS code for your business activity
- Estimated monthly taxable sales
Step-by-Step Registration Process
Step 1: Access MyTax Illinois
Visit mytax.illinois.gov to access Illinois’s online tax registration system.
Step 2: Create an Account
Create a MyTax Illinois account with your email and a secure password.
Step 3: Complete Form REG-1
The Illinois Business Registration Application (REG-1) covers multiple tax registrations including Retailers’ Occupation Tax (sales tax).
Step 4: Submit and Receive Certificate
Processing takes 5-10 business days. Your Certificate of Registration will be mailed and available online.
Common Mistakes to Avoid
- Not registering for all applicable taxes
- Forgetting Chicago/Cook County has additional taxes
- Missing owner information
Related Illinois Guides
Rates and Fees — Understand Illinois tax rates including Chicago.
Business Licensing — Other licenses your Illinois business needs.