A letter of testamentary—also known as letters testamentary—is a written order from a probate court approving the appointment of an executor under a will and authorizing the executor to administer the will and the decedent’s estate—including collecting amounts due to the estate, paying any outstanding debts of the estate, and distributing the assets of the estate in accordance with the provisions of the will.

Banks, brokerages, and mortgage and title companies rely on the court-ordered authority of the executor—as demonstrated by a letter of testamentary—when transferring ownership and control of assets in the testator’s estate.

When a deceased person (decedent) dies without a will (intestate) or the decedent’s will is found to be invalid by the probate court, the court may appoint an administrator to manage the estate, assets, and liabilities of the decedent. The administrator must be qualified or approved by the court and in some instances may be required to post a bond to secure the assets of the estate.

Upon appointment of an administrator by the probate court the court may issue letters of administration that authorize the administrator to administer the decedent’s estate by collecting amounts due to the estate, paying any outstanding debts of the estate, and distributing the assets of the estate in accordance with the state’s intestate succession laws.

Laws and procedures vary from state to state but an administrator—and the administrator’s administration of the estate—may be supervised or unsupervised by the probate court and may be with or without a bond required from the administrator.

In Louisiana, a letter of testamentary is a legal document issued by a probate court that authorizes an executor to administer a deceased person's estate in accordance with their will. This document is necessary for the executor to handle financial affairs such as collecting debts owed to the estate, paying outstanding debts, and distributing assets to beneficiaries as specified in the will. If a person dies intestate (without a valid will), or if the will is deemed invalid, the court will appoint an administrator for the estate. The administrator is tasked with managing the estate's assets and liabilities and must often be approved by the court, which may require them to post a bond. The court then issues letters of administration, which grant the administrator the authority to manage the estate according to Louisiana's intestate succession laws. The administration of the estate by the administrator may be subject to varying degrees of court supervision and may require a bond, depending on the specific circumstances and requirements of Louisiana law.