Illinois finally gets into the 21st Century! Effective for tax years ending on or after December 31, 2011, corporations, including S corporations, that are required to file their federal Forms U.S. 1120 and U.S. 1120S income tax returns by electronic means, are now required to file their Illinois returns through the IRS and Illinois Modernized Electronic Filing program (MeF). The Illinois MeF program currently supports the
2009 Form IL-1120, Corporation Income and Replacement Tax Return, and schedules (excluding unitary filings)
2010 Form IL-1120, and all schedules (including all unitary filings)
2011 Form IL-1120 and all schedules (in testing)
2011 Form IL-1120-ST, Small Business Replacement Tax Return, and all schedules (in testing)
In the event that you are required to file electronically for federal purposes and the Illinois MeF program does not support your return type, you are exempt from the requirement until such a time that we are prepared to include your return type (i.e., partnerships, trusts and estates, exempt organizations, composite returns, pass-through entities). Illinois MeF does not support any amended returns. Therefore, these returns are exempt from the new requirements.