How to Register for Sales Tax in Illinois

Businesses engaged in selling tangible personal property within Illinois are required to register with the Illinois Department of Revenue (IDOR). This registration is a requirement for legal operation, ensuring the business can properly collect and remit the state’s sales and use taxes.

Determining Your Registration Requirement

A business must register to collect Illinois sales tax once it establishes a significant connection, or “nexus,” with the state. This connection can be formed in two primary ways. The first is through a direct physical presence, which includes having a retail store, office, warehouse, or employees operating within Illinois. Storing inventory in the state, such as in a third-party fulfillment center, can also create a physical nexus.

The second way to establish nexus is through economic activity, even without a physical footprint. Illinois requires remote sellers to register if, in the preceding 12-month period, they have $100,000 or more in gross receipts from sales to Illinois customers. Once a business crosses this threshold, the obligation to register with the IDOR is triggered.

Information and Documents Needed for Registration

To complete the Illinois Business Registration Application (Form REG-1), you will need to gather several pieces of information beforehand.

• Your Federal Employer Identification Number (FEIN) or Social Security Number (SSN) for sole proprietors.
• The full legal name of the business and any “Doing Business As” (DBA) names.
• Your business structure (sole proprietorship, partnership, LLC, or corporation).
• The names, addresses, and SSNs for all owners, partners, or corporate officers.
• The date your business began, or will begin, making sales in Illinois.
• Your North American Industry Classification System (NAICS) code, which can be found on the U.S. Census Bureau website.
• Bank account details for setting up electronic tax payments.

The Registration Process

Online Registration

The recommended method for submitting your application is through the MyTax Illinois web portal. You will need to create a user profile and then proceed through a series of screens to input the information you gathered. Upon completion, you will receive an electronic confirmation of your submission. This is the faster method, with account information often available within one to two business days.

Mail-in Registration

For a paper application, you can download Form REG-1 from the IDOR website. Once completed, the form must be mailed to the address specified in its instructions. Be sure to use the most current version of the form to verify the mailing address. This method does not provide immediate confirmation and has longer processing times.

After You Register

Once the IDOR processes your registration, it will issue a Certificate of Registration (Form REG-8). This is your license to collect sales tax in Illinois and must be displayed at your place of business. A separate certificate is required for each business location.

The IDOR will also assign your business a sales tax filing frequency. This schedule can be monthly, quarterly, or annually, and is based on your anticipated volume of sales tax collected. Businesses with higher tax liabilities are required to file more frequently. You will receive notification of your first sales tax return due date, which begins your obligation to file returns and remit collected tax.