File individual and business taxes for Illinois by visiting the state's tax site, downloading form IL-1040 and mailing it to the state revenue department or by using the MyTax Illinois tool to file the forms electronically. Alternatively, residents can hire a third-party accountant to process the forms or use tax preparation software to submit the appropriate documents.
The Illinois Department of Revenue maintains a website that includes free digital copies of all the necessary forms to file personal and business income taxes as well as the subordinate forms for reporting items such as additional sources of income or estimated business taxes. The site divides its documents into two sections, with one focusing on individual taxes and the other on business taxes. Each section also contains instructions on how to fill out the forms, details about downloading and printing the documents and the deadlines for mailing the documents. The site also offers an electronic filing system that allows users to fill out the forms on the site and submit them electronically for free.
Many independent and franchise tax preparation firms also offer services that allow both individuals and businesses assistance with filing state taxes. For example, H&R Block operates numerous locations within the state and is able to file the tax returns on behalf of customers, often by mailing in paper forms. Similarly, programs such as TurboTax supports the same online filing features of the state's website, which include providing personal information to verify identity and serve as a signature.