Passphrase (25th word)

A passphrase, often called the 25th word, is an extra password combined with the recovery phrase. The same phrase with different passphrases gives entirely different wallets, and a wrong one raises no error.

The BIP-39 standard adds the passphrase to the text “mnemonic” and uses that to calculate the wallet’s seed. An empty passphrase gives the ordinary wallet. Any other gives a different, equally valid wallet, just an empty one. A typo shows no message. It simply opens a new, empty wallet.

A passphrase can be a word, a sentence or any string of characters. It isn’t part of the recovery phrase and no device generates it: you invent it yourself. It protects against someone who finds the phrase alone. But it adds risk, because nothing can fix losing it.

You store it separately from the phrase. If both sat in one place, the point would be gone.

Why it matters for your family

A family that finds the phrase and doesn’t know about the passphrase will see an empty wallet and conclude there’s no bitcoin. It’s one of the most common ways to lose funds. If you use a passphrase, the instructions must say so clearly and point to where it’s written down. The guide on the passphrase covers details and good practice.