The affidavit is often coupled with a copy of the death certificate. The affidavit can then be used to complete the distribution of property.To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. "Letters of Office" is not really a letter. The Petition for Letters of Administration is the document that is used when the decedent died without a will. If the decedent dies without a Will, a Petition for Letters of Administration is filed. When you die without a will in Illinois, your estate will undergo the probate process. If one dies without a Will, he or she dies "Intestate. " Since, there is no Will to file, there is no individual specifically identified as an executor. FindLaw explains the probate process when someone dies without a will, detailing appointing an administrator, settling debts, and distributing assets.