In general, Form IL-990-T, Exempt Organization Income and Replacement Tax Return, is due on or before the 15th day of the 5th month following the close of the tax year. If you are an employee trust as described in IRC Section 401(a), you must file Form IL-990-T on or before the 15th day of the 4th month following the close of the tax year.
Automatic extension - If your tax year begins on or after January 1, 2016, and you are taxed as a:
- 401 (a) trust, we grant you an automatic six-month extension of time to file your tax return.
- Corporation or 501(c) trust, we grant you an automatic seven-month extension of time to file your tax return.
For tax years beginning before January 1, 2016, see the instructions which correspond to the year of the return you are filing.
You are not required to file Form IL-505-B, Automatic Extension Payment, in order to obtain this automatic extension. However, if you expect tax to be due, you must use Form IL-505-B to pay any tentative tax due in order to avoid interest and penalty on tax not paid by the original due date of the return. An extension of time to file your Form IL-990-T does not extend the amount of time you have to pay your Illinois tax liability.