What is a seed phrase?

A seed phrase (also called a recovery phrase) is a list of words that can restore a wallet. If you have found one after a death, it is the single most sensitive item in the estate.

What it is

A seed phrase is usually 12 or 24 words generated when a wallet is set up (BIP-39; other standard lengths are 15, 18 and 21). With those words, in the exact order, the wallet and its funds can be restored on any compatible device or software. The phrase is the master backup, the device itself is not. The balance does not live “in” the wallet at all; the wallet only provides access to crypto recorded on the blockchain.

Why the order matters

The words are not a password list; their order is part of the key. The same words in the wrong order restore nothing. A partial phrase may be completable only when enough words are known, never assume it is. Older or non-standard wallets may use their own formats that do not follow the usual word lists.

The standards

• BIP-39: the common 12- and 24-word format.
• SLIP-39: Shamir shares, a backup split into multiple shares (commonly 20 words each). Shares are not multisig keys and are not interchangeable with a seed phrase.

How it relates to other access components

Access to crypto is usually made up of several parts at once:

• a device plus a PIN;
• the seed phrase (on paper or in a safe);
• possibly a passphrase, an extra word that changes which wallet the seed phrase opens;
• the correct software version.

This means someone can be the lawful heir and hold the seed phrase and still not reach the funds without the passphrase, and the reverse: whoever holds the phrase but is not authorised must not use it. Possession of the seed phrase means technical access, not ownership.

If you found one

• Preserve it: flat, dry, out of sight. Never photograph or type it anywhere. The only legitimate place it is entered is the official device or wallet software from the official channel that you are certain is genuine, after authority is confirmed.
• It proves technical access, not legal authority.
• Never enter it on a website, in an app or in a message, and never send it to anyone.
• Record only that it exists and where it is kept, never the words themselves.

For how to handle the item you found (and how a found list differs from a passphrase) see what did you find? and wallet passwords and passphrases.

What to do with it

• The words themselves are the access, in the exact order, together with the passphrase if one was set.
• When the estate is ready: the words restore the wallet in compatible software or hardware. This is done on the device itself or offline, never entered into a website, app or message.
• The classic mistake: typing or photographing the words online, missing the passphrase (an intact phrase can open an empty wallet), or getting the order wrong.
• If the phrase is incomplete: a few missing words can sometimes be reconstructed, read what is realistically possible in wallet recovery.
• Until authority is confirmed, preserve the words flat, dry and private.

For the full index of every wallet format and its deep guide, see the wallet format library.

New to these terms? Plain-language definitions are in the crypto inheritance glossary.