Seed phrase (recovery phrase)

If your phone or hardware walletGlossaryHardware walletA small dedicated device that keeps your private keys offline and signs transactions internally. The key never leaves the device, so malware on your computer can’t get at it.On the learning path: Stage 6 · Step 1 – Hardware wallets compared →In the glossary →× breaks or gets lost, you enter the words in a compatible wallet to restore all your private keysGlossaryPrivate keyA secret, randomly generated number that you use to sign transactions and so control your bitcoin. Anyone who knows the private key can spend the bitcoin that belongs to it – it must never fall into anyone else’s hands.On the learning path: Stage 5 · Step 3 – Backing up your seed phrase →In the glossary →× – and with them your funds. The common standard for this is BIP 39GlossaryBIP 39 (standard for seed words)The widely used standard that turns random data into 12 to 24 words from a fixed list of 2,048 words. Your wallet calculates all its keys from these words – BIP 39 is behind most seed phrases.On the learning path: Stage 5 · Step 3 – Backing up your seed phrase →In the glossary →×: a fixed list of 2,048 words, usually in English.^[1] An optional passphraseGlossaryPassphrase (the ‘25th word’)An extra word of your choice added to your seed phrase. The same words then produce a completely different wallet. This protects you if someone finds your words – but if you forget the passphrase, access is lost for good.On the learning path: Stage 5 · Step 3 – Backing up your seed phrase →In the glossary →× turns the same words into a different wallet.

What to watch out for

• Never share the words or type them into a website. Anyone who knows them can take your bitcoin – and you will practically never get it back. Scammers pose as support staff, wallet providers or friends to get hold of the words. Legitimate companies never ask for them.^[2]
• Back them up offline only: on paper or a metal backupGlossaryMetal backupA backup of your seed phrase on steel or titanium – punched, engraved or made with letter tiles. Unlike paper, it survives fire and water. Independent tests show that simple stainless steel plates are robust and often the cheapest.On the learning path: Stage 5 · Step 3 – Backing up your seed phrase →In the glossary →×, with the words numbered, and at least two copies in separate places. No photo, no cloud, no notes app.
• Let your wallet generate them: if a device already comes with a seed phrase, someone else knows it too – don’t use it.
• Write down the wallet and address type as well: this isn’t secret and helps if different software doesn’t find the derivation pathGlossaryDerivation pathThe route a wallet follows to calculate individual keys from your seed phrase, for example m/84'/0'/0'. If another wallet uses a different path when you restore, it looks empty – even though nothing has been lost.In the glossary →× on its own.
• Test the recovery before you send larger amounts to the new wallet.