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 Wisconsin, a letter of testamentary is a legal document issued by a probate court that grants an executor the authority to administer a decedent's estate as specified in the will. This includes managing the estate's assets, settling debts, and distributing the remaining assets to the beneficiaries according to the will's instructions. If a person dies intestate (without a valid will), or if the will is deemed invalid, the court may appoint an administrator to manage the estate. The administrator is tasked with similar responsibilities as an executor but must distribute the assets according to Wisconsin's intestate succession laws. The court may issue letters of administration to the appointed administrator, which serve a similar purpose to letters testamentary. The process of estate administration in Wisconsin can be either supervised or unsupervised by the probate court, and the administrator may be required to post a bond, depending on the circumstances of the estate and the court's discretion.