Gather required supporting documents.The list of pertinent documents depends on the type of transaction the filer is applying for and on the information they entered in their application online.Complete the application.While completing an application, an individual must designate certain types of data, such as owner information, vehicle information, insurance, information about lienholder (if applicable), etc.In order to complete the transaction successfully, the applicant should follow a few simple steps: The system allows filers to fill in the application and print it. An Illinois Application for Vehicle Transaction(s) can only be filled out through the ERT System.