Letters testamentary are obtained from the appropriate county courthouse as part of probate. The appropriate court is the court in the county in which the decedent lived when he died. They are the documents that show who has the legal authority to handle the affairs of a decedent.
Letters testamentary are issued when the decedent had a will. The individual named as executor in the will presents the official will, a certified copy of the death certificate and a probate petition at the courthouse. When the court validates the will and opens probate, the executor takes an oath to fully administer the estate. Letters testamentary are then provided, giving the executor authority to identify heirs, open bank accounts, pay debts and sell assets as necessary to settle the estate.
When the decedent had property located in more than one state, probate may have to be opened in each state, each court providing its own letters testamentary.
If the decedent didn't have a valid will, the estate is overseen by an administrator rather than an executor. This is usually a surviving spouse or the next-closest relative. The document of authority is a letter of administration or letter of representation. The administrator follows the applicable state laws of intestacy to settle and distribute the estate.