C-Corporations – calendar year | April 15 | 5-month automatic extension (September 15) until 2026, then 6-month |
C-Corporations – fiscal year other than June 30 | 3 ½ months after year-end | 6-month automatic extension |
C-Corporations – June 30 year | September 15 (until 2026, then October 15) | 7-month automatic extension (April 15) until 2026, then 6-month |
Partnerships | March 15 for calendar-year returns, or 2 ½ months after close of year-end | 6-month maximum extension (September 15 for calendar-year returns) |
S-Corporations | March 15 for calendar-year returns, or 2 ½ months after close of year-end | 6-month maximum extension |
Trust Form 1041 – calendar year | April 15 | 5 ½ month maximum extension |
Trust Form 1041- non-calendar year | 3 ½ months after year end | 5-month maximum extension (6-month for certain types of trusts) |
FinCEN Foreign Bank Account Reporting (FBAR) | April 15 | 6-month maximum extension |