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 must be treated as highly sensitive access material and a high-risk secret.

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 can be restored in compatible wallet software; whether the funds appear also depends on the correct derivation path and any passphrase. Another wallet may accept the words but show an empty balance.

A recovery phrase is important, but it does not always restore every account or all wallet data. Imported accounts, other recovery phrases or other access material may be needed separately. So also preserve the original device and the wallet configuration until it is clear that all relevant accounts have been safely recovered. 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. A different order does not reproduce the intended wallet and will often not form a valid mnemonic; some wrong sequences can even be accepted as a valid mnemonic and then show a different or empty wallet. Never treat acceptance by software as proof that the order is correct, and never conclude from a divergent result that the original wallet was empty. 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 optional extra value that, together with the words, determines the final seed; any other passphrase leads to a different valid wallet;
• suitable wallet software or hardware that supports this recovery phrase.

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. A seed phrase is important technical access material, but does not always mean the intended wallet or funds are independently accessible with it. Depending on the configuration, a passphrase, additional shares, other signatories or other recovery data may also be needed. Holding a seed phrase moreover proves no legal authority or ownership.

If you found one

• Preserve it: flat, dry, out of sight. Never photograph or type it anywhere. Enter it only within a pre-verified and suitable recovery environment: compatible wallet software or hardware from a trusted official channel, or a controlled offline environment when specialist recovery is needed.
• It is important technical access material, but does not prove that full technical access exists, nor that the holder is legally authorised.
• Never enter recovery material into an unknown or not independently verified website, app, form, chat or tool, and never send it to anyone without a clear reason; use it only when actually needed within the verified recovery procedure of the wallet or device concerned.
• 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 only within the verified recovery procedure of the wallet concerned, for example on the device itself or in verified software, never in an unknown website, app or tool.
• 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 index of the wallet formats covered in this library and its deep guide, see the wallet format library.

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