letters testamentary

Definition from Nolo’s Plain-English Law Dictionary

The document a probate court issues to an executor (personal representative) of a deceased person's estate, authorizing the executor to settle the estate according to the terms of the person's will. Banks, brokerages, and government agencies often require a certified copy of the letters before accepting the executor's authority to collect the deceased person's assets. (See also: letters of administration)

Definition provided by Nolo’s Plain-English Law Dictionary.