The Illinois Department of Revenue (IDOR), in conjunction with the Internal Revenue Service (IRS), accepts electronically filed business income tax and individual income tax returns as part of the IRS Modernized e-File (MeF) Program. MeF is a web-based system that allows electronic filing of tax returns through the Internet. MeF uses the widely accepted Extensible Markup Language (XML) format.
Linked (combined) federal/state filings and unlinked (state-only or state standalone) returns, along with payments (estimated payment(s) and tax return payments) are allowed to be filed through MeF. The Illinois MeF program for individual income tax will accept and process the current year IL-1040 and two years prior IL-1040.
All entities wishing to participate must register with the IRS and be accepted in order to participate in MeF. Software developers are required to register and test their product with IDOR.
Electronic Return Originators (ERO’s) and transmitters are not required to submit a separate Illinois enrollment application for authorization to file Illinois Individual Income Tax Returns electronically. e-File providers approved in the IRS Electronic Filing Program are automatically enrolled in the Illinois program.
Software developers must submit Form IL-8633-I, Application to File Illinois Individual Income Tax Returns Electronically for Software Developers, to register or update registration information. Software developers are required to test their product and have it approved by Illinois. Software developers should call 1 217 524-4767 when they are ready to begin testing or have questions.
Important Program Information
IL-1040 for Software Developers