The department has the ability to electronically receive and process the
Participation in the Illinois Electronic Filing Program for sales and related tax returns is available to software developers, transmitters, Electronic Return Originators (EROs), and taxpayers. To enroll, complete Form IL-8633-B, Business Electronic Filing Enrollment. Note: Participants using our free MyTax Illinois program do not complete Form IL-8633-B.
To use this method of electronic filing, you can write your own software or buy software from an accepted electronic filer (third party). If you wish to create your own software for filing or create software to sell, please refer to the corresponding implementation guide below. Once we have received your IL-8633-B enrollment form, we will contact you regarding testing.
Form ST-1 electronic filing documentation (version ST1V2.0)
Form ST-4 electronic filing documentation (version ST4V1.0)
Form ST-8 electronic filing documentation (version ST8V1.0)
Form ST-14 electronic filing documentation (version ST14V1.0)