An estate administrator must file the final tax return for a deceased person separate from their estate income tax return. You must file Form ET-706 within nine months after the decedent's date of death, unless you receive an extension of time to file the return.Find common questions and answers about estate taxes, including requirements for filing, selling inherited property and taxable gifts. New York State's estate tax is calculated using the tax table provided on Form ET706. There are multiple versions of Form ET-706. You will have to file all necessary tax forms and open a checking account in the name of the estate to pay any estate expenses. When filing as an executor of estate, on the Form 1040, include only income and expense items up to the date of death. The income tax return form for estates is IRS Form 1041. It's also called a "fiduciary" return, because you file it in your capacity as executor of the estate. All required New Jersey Estate Tax returns must be filed within nine (9) months of the date of a resident decedent's death.