The IRS form used to apply for an automatic six-month extension of time in which to file an IRS Form 706, United States Estate (and Generation-Skipping Transfer) Tax Return, as well as IRS Forms 706-A, 706-D, 706-NA and 706-QDT. Form 4768 is also used to request an extension of time to pay federal estate taxes.
Form 4768 must be filed on or before the due date for Form 706, which is due on or before nine months after a deceased person's date of death. Thus, timely filing a Form 4768 will give an executor 15 months from the date of death within which to file Form 706.
For the 2011 and 2012 tax years only, surviving spouses who want to elect to make use of their deceased spouse's unused federal estate tax exemption must timely file Form 706 for their deceased spouse's estate. By timely filing Form 4768, the surviving spouse will have 15 months from the deceased spouse's date of death within which to make the election.
Follow this link to view the latest version of IRS Form 4768: Application for Extension of Time To File a Return and/or Pay U.S. Estate(and Generation-Skipping Transfer) Taxes