Key takeaways
- Form 4768 gives an automatic six months to file Form 706 when it is filed by the original due date.
- A payment extension is a separate request on Form 4768, and interest runs from the original due date regardless.
- The Form 709 instructions list Form 8892, Form 4868 and Form 2350, not Form 4768.
- New York uses Form ET-133 for its own extension, for decedents who died on or after January 1, 2025.
Calculate the Form 706 due date first
Form 706, the federal estate and GST tax return, is due nine months after the date of the decedent's death, according to the Instructions for Form 706 revised 07/2026. An estate with a date of death of March 15, 2026 has an original due date of December 15, 2026.
A death before February 10, 2026 means the Form 706 due date has already passed as of November 10, 2026. The automatic extension is no longer available for that return, because Form 4768 for the automatic extension must be filed by the original due date. Those estates need a for-cause request with a written statement explaining in detail why the automatic extension was not requested.
Take the date of death from the death certificate and the probate filing, and put the due date on the calendar the day the executor is appointed. A wrong date of death moves every later deadline.
Use Form 4768 for the automatic extension
Form 4768 is the IRS application for more time to file Form 706, Form 706-A, Form 706-NA or Form 706-QDT. The automatic extension is six months, and the instructions say to file Form 4768 by the original due date of the return.
Using the March 15, 2026 example, file Form 4768 by December 15, 2026. The return is then due June 15, 2027, six months after the original due date.
A for-cause extension runs six months from the original due date, not from the day Form 4768 is filed. The for-cause and additional requests are discretionary. An additional extension is available only if the executor is out of the country.
Keep the payment request separate
An extension to file does not extend the time to pay. A payment extension under section 6161 is a separate request in Part III of Form 4768, and the instructions say a separate Form 4768 is needed for it.
When requesting an extension of time to pay, do not send Form 4768 with Form 706. The payment extension may not exceed 12 months. For reasonable cause it may be granted one year at a time, up to a maximum of 10 years.
Interest must be paid on any estate tax not paid in full by the original due date, regardless of whether an extension of time to file or pay has been obtained. An estate that files on June 15, 2027 with tax still unpaid owes interest from December 15, 2026, even with the filing extension in place.
If the return is not yet filed, the Form 4768 instructions say to estimate the tax. If it has already been filed, attach a copy of the return instead.
Handle Form 709 with its own forms
Form 709 is due not later than April 15 of the year after the gift was made. A gift made in 2026 has a Form 709 due date of April 15, 2027, according to the Instructions for Form 709 (2025).
Form 4768 is not on the Form 709 list. The instructions name Form 8892 for an automatic 6-month extension of the gift tax return when the donor does not extend the income tax return. A 2026 gift with no income tax extension moves to October 15, 2027 with Form 8892 filed by April 15, 2027.
If the donor files Form 4868 or Form 2350 for the income tax return, that also extends the gift return, but only if the income tax extension is requested too. Form 8892 also works as the payment voucher if gift tax is owed, and a Form 709 extension does not extend the time to pay.
New York: Form ET-706 and Form ET-133
The New York return is Form ET-706, the New York State Estate Tax Return, for decedents who died on or after January 1, 2025. The extension request is Form ET-133, the Application for Extension of Time to File and/or Pay Estate Tax, for the same group of decedents.
The federal Form 4768 is not the New York request. Send Form ET-133 for the state extension even when the federal Form 4768 is already filed. The Form ET-133 title covers both filing and paying, so check which request the estate actually needs.
If the estate will owe New York tax and cannot pay by the due date, check whether a tentative payment on Form ET-130, Tentative Payment of Estate Tax, is needed for the year of death. Read the New York instructions for that year before you put a New York date on the client calendar.
Failure modes and fixes
The Form 4768 is filed after the original due date and the preparer still counts on six more months. Fix it by checking the original due date at intake, and if that date has passed, file the for-cause request with a written statement.
The payment request is attached to the Form 706 package. Fix it by filing the payment request on its own Form 4768 and keeping it out of the return package.
The federal payment extension is assumed to cover New York. Fix it by filing Form ET-133 separately and calendaring the New York date from its instructions.
A Form 709 is extended with Form 4768 because the same preparer handles the estate. Fix it by using Form 8892 for the gift return, and Form 4868 or Form 2350 only when the income tax return is also extended.
What to send the executor
Send the executor a short note with the due date, the request and the payment position. For example, write: "The Form 706 is due December 15, 2026. We will file Form 4768 before that date to extend the filing to June 15, 2027." Then add that interest runs from December 15, 2026 on any tax not paid by then, and ask the executor to confirm the amount the estate can pay now.
Ask for the date of death, the executor's authority documents, the estimated gross estate and the amount of tax expected. Those four items are enough to set the due dates and decide whether a payment request is needed.
Keep a copy of the Form 4768 as filed, the date it was filed and the proof of delivery. The record shows the request was made by the original due date.