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Modernized e-File (MeF) for Individual Income Tax

General Information

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. In addition, starting with the 2021 tax year, the Illinois MeF program for individual income tax will accept and process the IL-1040-X.

All entities wishing to participate must register with the IRS and be accepted 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.

For additional information about Modernized e-File (MeF) for Individual Income Tax, please visit the Program Information page.  

IL-1040 for Software Developers

Test cases, schemas, and business rules are located on the FTA's State Exchange System (SES). To request access to the SES, email your user's name and email address to You will need to complete the Tax Software Provider Illinois Department of Revenue Letter of Intent, submit it to, and obtain approval to access the test cases, schemas, business rules, and developer guide.