| Tax Return Liability Period: 01/01/2016 - 12/31/2016 |
|
|---|---|
| Test transmissions will be accepted: | December 8, 2016 |
| Production transmissions will be accepted: | January 23, 2017 |
| Last date for timely paid IL-1040 returns: | April 18, 2017 |
| Last date to transmit timely filed IL-1040 returns: | October 16, 2017 |
| Illinois electronic filing system shuts down: | November 30, 2017* |
| Retention of acknowledgment file materials: | December 31, 2017 |
| Retention of electronic return-related materials for non-paid preparers: | December 31, 2017 |
| Retention of electronic return-related materials for paid
preparers: (Including original Forms IL-8453 and attachments) |
3 years |
