For paper returns, the filer should write the word deceased, the deceased person's name and the date of death across the top. There are multiple versions of Form ET706.Be sure to use the version that corresponds to the decedent's date of death. It shows how to complete and file federal income tax returns and explains their responsibility to pay any taxes due on behalf of the decedent. If paper-filed, write "Deceased," the taxpayer's name, and the taxpayer's date of death across the top of the final return. Inheritance tax payments are due upon the death of the decedent and become delinquent nine months after the individual's death. Tell us about a bereavement. Filing income tax for the deceased. The income earned up to the date of death is subject to income tax. Formal proof of death is required at various steps in the probate process, and the standard proof is a certified death certificate.