The following extended tax returns are due on October 15, 2019:
Individuals: Form 1040.
Corporations: Form 1120.
Employee Benefit Plans: Form 5500 series (or Form 5558 for a 3-month extension).
Please note that this applies to calendar year filers only. If your year end is not December 31st, you are a fiscal year filer and your extended due date is different.
For corporations that are fiscal year filers, the extended due date is 6 months following the close of the tax year, UNLESS the year-end is June 30th, in which case the extended due date is April 15th, 2020.
For employee benefit plans that are fiscal year filers, the extended due date is the 15th day of the 3rd month following the original due date.
The following common extended tax forms are also due on October 15, 2019:
Form 709: Gift Tax Return.
FinCEN Form 114: Report of Foreign Bank and Financial Accounts.