Why it matters
If your family doesn't know the vault exists or where to find the backup and password, they can't use it when they need it. A short conversation and a written note in a safe place can make all the difference.
What to tell them
You don't have to share the contents. Tell them you've put important information in a secure app called Local Legacy Vault, that there's a backup (e.g. on a USB in the safe), and that they'll need your master password—which you've stored in a sealed envelope with your will or in another agreed place. That way they know what to look for and who has permission to open it.
When to have the conversation
Many people do it when they set up a will or power of attorney, or during a calm moment when the family is together. You can keep it brief: "I've organized everything in one place so you won't have to search. When the time comes, here's where to find it."
Tip: Add an entry in your vault that says who to contact first and where the backup and password are stored. That way, if one person forgets, the information is still in the vault for whoever has access. See Sharing with Family for how access and executors work in the app.