3.7 Seed Phrases, Backups & Inheritance

A seed phrase is 12 or 24 ordinary English words that fully represent your Bitcoin keys. With those words and nothing else, anyone (you, a thief, an heir) can recreate the wallet from scratch on any compatible device. Treat them with at least the same care you'd treat the deed to your house.

Backup basics:

• Write the seed words down BY HAND. Never type them into a computer, phone, photo, email, cloud notes, password manager, or screenshot. Anything that touches the internet is a potential leak.

• Make at least two physical backups, stored in different locations. Paper is fine short-term; metal is far better long-term (fireproof and waterproof). Trusted metal options include Seedplate, Cryptosteel, Blockmit, and Stamp Seed.

• Consider an extra 'passphrase' (sometimes called the 25th word) — a secret you add on top of the seed. Even if someone finds the seed alone, without your passphrase the wallet shows as empty.

Inheritance planning matters even more for self-custody than for traditional savings. If you get hit by a bus tomorrow with no plan, the coins are gone forever.

Approaches, from simplest to most robust:

1) A sealed letter with your spouse or attorney explaining what to do (where the seeds are, what device they're on, who can help). Pair with a 2-of-3 multisig so no single envelope is enough to steal.

2) A time-locked recovery branch (using Miniscript-based wallets like Liana): your key normally spends alone, but if you don't move coins for, say, a year, your heir's key starts working too — automatically.

3) Collaborative custody services like Casa, Unchained, or Nunchuk: they hold one key of a multisig as a safety net and handle inheritance paperwork while you still control the majority of keys.

Rule: never store complete instructions and complete seeds in the same place. Split the information so a single discovery can't drain everything.