To activate your MyTax Illinois account, you must go to mytax.illinois.gov, click "Sign Up," and complete specific information about yourself and your company.
If you are setting up an account for an individual or are a Sole Proprietor who is adding their Individual Income Tax account; a Letter ID will be required to create the account. The Letter ID you enter must have been issued within the last 90 days. If you do not have a letter ID, use the "Request a letter ID" feature on the Individuals menu of the MyTax Illinois home screen to have a letter sent to you. You will not be able to create your account until you receive the letter ID.
Note: You cannot activate a MyTax Illinois individual income tax account if you are a first-time filer.
After receiving the letter ID and setting up your account, IDOR must verify your submitted information—which usually takes a minute or two. Then, IDOR will send a message to the email address you provided giving you the authentication code needed for your initial login.
Note: The authentication code is only required for your first login. For step-by-step instructions and troubleshooting, see the Authentication Guide.
For more information see the MyTax Illinois Help Guide.