A letter of instruction (LOI), also called a letter of intent. It provides your executor with important information about your assets and personal information.Quickly learn what a Letter of Instruction is and how to write one (2024 updated). Plus, grab the free template so you can take action! The letter of instruction is intended only to provide supplemental information to be helpful or informative to your executor or personal representative. This guide is designed to teach you how to write a letter of instruction for heirs, or anyone else who may benefit from a little more direction. A bank letter is an official document from your bank that provides important information about your business' official bank account. Letters of instruction have become an important component in the estate planning process. If your executor has easy access to your banking details, it could also be kept in a bank lockbox. Services Account Number as provided in the Financial Services Delivery.