New York State's estate tax is calculated using the tax table provided on Form ET706. There are multiple versions of Form ET-706.File the final income tax returns of a deceased person for current and prior years, pay any balance due and claim the refund. File an estate income tax return. File Form 706 for the estates of decedents who were either. U.S. citizens or U.S. residents at the time of death. In New York State, the Surrogate's Court decides what happens to a person's property when that person dies. Estates must file and pay the tax within nine months after the decedent's death using Form ET-706, New York State Estate Tax Return. However, as part of your deceased beneficiary packet, you will also be required to submit a W-8BEN to OPA for tax purposes. This guide covers how to file and pay your estate tax return; including how to calculate the maximum federal credit.