The IRS, with this private letter ruling, granted a surviving spouse (as executor) the right to make a late portability election for the amount of the deceased spouse's unused exclusion amount (DSUEA). The IRS determined that it had discretion to allow a late election in this situation because the estate was not required to file Form 706. The IRS has no discretion to allow a late election when the due date is set by statute as it is, for example, for estates that have a filing requirement due to being a taxable estate. The IRS also noted that if it is later determined that the estate exceeded the amount required to file an estate tax return that portability would not be allowed because the IRS, in that situation, would be unable to grant relief. Priv. Ltr. Rul. 201536005 (Jun. 4, 2015).