Businesses
 
 
 
 
 

How do I Register my Business?

 
 

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You must register with the Illinois Department of Revenue if you conduct business in Illinois, or with Illinois customers. This includes sole proprietors (individual or husband/wife), exempt organizations, or government agencies withholding for Illinois employees.


To Register

Register with IDOR before you make any sales or when you hire an employee. For those businesses that have sales or use tax liability in Illinois, you will receive a Certificate of Registration that must be displayed in a prominent location in the place of business to which it applies. To register your business and receive your Certificate of Registration and Illinois Business Tax number (i.e., your “tax” number or IBT no.), you have these options:

  • Register electronically with on-line Business Registration application (1-2 days)
  • Complete and mail Form REG-1, Illinois Business Registration Application (6-8 weeks)
  • Visit a Regional Office where your application will be processed in 1 to 2 business days.

Note: Certain tax types may have additional registration or bonding requirements. If additional information is required for your particular registration, the department will contact you.

Note: Illinois Business Tax (IBT) numbers eventually will be replaced by Account IDs when that tax is included in the new system. At the end of the four-year transition period, use of the term “IBT” will be discontinued.

It is recommended that you contact other federal and state agencies and your units of local government (county, municipal, mass transit districts, etc.) to learn if you must register your business with them.


Find answers to your frequently asked tax questions and more with our Taxpayer Answer Center. If you are unable to find your answer after searching the Taxpayer Answer Center, you will be able to email us through this system by clicking the "Send an Email" Tab at the top of the screen.

In addition, you may find your answers using our new and improved Search engine.

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