Tax due dates
Every deadline that might be yours, on the day it actually falls this year — not the day the rule prints. Federal, plus the New York and New Jersey dates that run on their own calendar.
Next up: C corporation fourth instalment of estimated tax on Tue, December 15.
- Jan15Thu
Last instalment of estimated tax for the year just ended1040-ES
Skip it if you file the return and pay in full by 31 January.
- Mar16Mon
Partnership and LLC returns1065
Extension: Six months, to 15 September
This is the one people miss. It is a month before the personal deadline, and the penalty runs per partner per month.
Printed as the 15th — moved because it falls on a weekend or holiday.
- Mar16Mon
S corporation returns1120-S
Extension: Six months, to 15 September
Printed as the 15th — moved because it falls on a weekend or holiday.
- Mar16Mon
Electing S corporation status for this year2553
Two months and fifteen days from the start of the tax year. Miss it and the election waits until next year.
Printed as the 15th — moved because it falls on a weekend or holiday.
- Mar16Mon
Electing into the New York pass-through entity tax for this yearNew York
There is no late election and no relief for missing it — the year is simply gone. An owner has to make it themselves in the entity's Online Services account; the state does not permit your accountant to make the election for you.
Printed as the 15th — moved because it falls on a weekend or holiday.
- Mar16Mon
Last year's PTET return, and this year's first PTET estimated paymentNew York
Extension: Six months to file, to 15 September — not to pay
Printed as the 15th — moved because it falls on a weekend or holiday.
- Mar31Tue
Other 1099s filed electronically1099-MISC
- Apr15Wed
Personal returns1040
Extension: Six months, to 15 October
An extension gives you more time to file, never more time to pay. Interest runs from April whatever you do.
- Apr15Wed
Gift tax returns709
Extension: Follows your personal extension, to 15 October
- Apr15Wed
Report of foreign bank accountsFinCEN 114
Extension: Automatic, to 15 October — nothing to file for it
- Apr15Wed
C corporation returns1120
Extension: Six months, to 15 October
- Apr15Wed
First instalment of estimated tax1040-ES, 1120-W
- Jun15Mon
Second instalment of estimated tax
Two months after the first, not three. The quarters are not quarters.
- Jun15Mon
PTET estimated paymentNew York
- Jul31Fri
Retirement plan returns5500
Extension: To 15 October
- Sep15Tue
Partnership and S corporation returns, on extension1065, 1120-S
- Sep15Tue
Third instalment of estimated tax
- Sep15Tue
PTET estimated paymentNew York
- Oct15Thu
Personal and C corporation returns, on extension1040, 1120
The last one. There is no further extension.
- Dec15Tue
C corporation fourth instalment of estimated tax
- Dec15Tue
PTET estimated paymentNew York
The last chance to put the deduction into this year. The money has to be paid in by 31 December to count, and after 15 December the state will not let you schedule a payment in advance.
Calendar-year filers. Most of this is federal; anything marked New York or New Jersey is there because that state’s date does not follow the federal one and so cannot be worked out from it. A fiscal year moves nearly all of it.
5 of these do not fall on the date the rule prints, because 2026 puts them on a weekend or a holiday. They are shown on the day they are actually due.
The state holiday calendars are not quite the federal one — New Jersey closes for Good Friday, the IRS keeps Emancipation Day. Neither changes a date on this list, but in a year where something lands oddly, ring us rather than assume.
An extension buys time to file, never time to pay. Interest and the late-payment penalty run from the original date on anything still owing — so an extension with nothing paid is a more expensive way to be late.