Administration is the process where the Surrogate's Court officially gives out Letters of Administration to a qualified distributee (heir) of the Decedent. There are multiple versions of Form ET706.Be sure to use the version that corresponds to the decedent's date of death. Find common questions and answers about estate taxes, including requirements for filing, selling inherited property and taxable gifts. 9 months after the date of the decedent's death. It is not a form you can obtain online or fill out yourself. You should also complete and file with the final return a copy of Form 1310, Statement of Person Claiming Refund Due a Deceased Taxpayer.