What Is a Letter of Instruction (and Why It's the Easiest Estate Document to Finish)

A letter of instruction has no legal weight. A court won't enforce it. A bank won't accept it as authorization. It doesn't need a signature witnessed by anyone. That's usually stated as a limitation. It's actually the reason the document is so useful.

A will, a power of attorney, a living will: all three are legal instruments, and all three are narrow on purpose. They cover specific decisions: who inherits what, who acts on your behalf, what medical care you do or don't want. Nothing else. None of them say where the safe deposit box key is. None say which of your accounts auto-pays the mortgage, or that you'd rather be cremated near the lake your family visits every summer.

A letter of instruction covers exactly that gap. It's the practical, personal information that matters enormously to the people handling things, information no legal document is built to hold. Account locations, password pointers (not the passwords themselves), funeral preferences, who to call first, what to tell the kids. Nothing here needs a lawyer's signature. It just needs to exist somewhere findable.

The informal nature is also why it's so easy to put off. Nothing forces you to write it, the way a will forces a decision about inheritance. That's the actual argument for doing it now instead of eventually. It's the one estate document with zero legal friction standing between you and finishing it today.