What Is a Seed Phrase? How to Store It Safely

A seed phrase is the master backup of a self-custody crypto wallet: a list of usually 12 or 24 words that can recreate every key in it. Anyone who has those words controls the coins, on any compatible wallet. Keep it offline, on paper, and never share or type it anywhere else.

This guide explains what a seed phrase is, how the words are generated, what an optional passphrase adds, how XRP Ledger wallets such as Xaman handle the same idea, and how to store your backup so it survives theft, accidents and your own forgetfulness.

What is a seed phrase?

A seed phrase is the master backup of a crypto wallet. It is a list of ordinary words, usually 12 or 24, that encodes the secret from which every private key in the wallet is derived. You may also see it called a recovery phrase, secret recovery phrase or mnemonic.

The important point is that the phrase is not a password for an app. It is the wallet. Enter the same words into compatible software anywhere in the world, and the same addresses and balances appear, with full power to move them. That is what makes it useful when a phone breaks, and dangerous when someone else sees it.

How does a seed phrase work?

Most wallets follow a public standard called BIP-39 (Bitcoin Improvement Proposal 39). According to the specification:

• The wallet generates a random number, then converts it into words from a fixed list of 2,048.
• A phrase can be 12, 15, 18, 21 or 24 words long. Longer phrases carry more randomness.
• The last word includes a short checksum, a built-in check that catches most typos when you restore. It can’t correct them.
• The words are then run through a one-way process to produce the seed that creates all your keys.

Because it is a shared standard, a phrase made by one BIP-39 wallet can usually be restored in another. That is convenient, and it is also why a stolen phrase can be used on any compatible wallet.

Phrase length	Randomness (BIP-39)
12 words	128 bits
18 words	192 bits
24 words	256 bits

Either length is far beyond guessing when the device generates it properly. The realistic risk is the copy you keep.

What is a passphrase, or 25th word?

A passphrase is an optional extra word or phrase you choose, added on top of your seed phrase. The BIP-39 standard lets every possible passphrase produce a valid wallet, so each one opens a different set of accounts.

Ledger’s explanation of the feature describes it as a separate group of accounts that your seed words alone can’t reach. That can protect you if someone finds your paper backup but not the passphrase. The cost is real:

• The wallet maker doesn’t store it. Ledger says that if you lose or forget it, those hidden accounts become inaccessible.
• It must match exactly. Ledger notes that the passphrase is case-sensitive.
• A wrong passphrase doesn’t show an error. It simply opens a different, empty wallet, which can be alarming if you don’t expect it.

A passphrase is an advanced tool. If you use one, it needs its own backup, stored separately from the seed words.

How do XRP Ledger wallets like Xaman handle this?

Xaman, a widely used XRP Ledger wallet, uses secret numbers instead of words for accounts it creates. According to Xaman’s help center, they appear as eight rows labeled A to H, each with six digits, and you write them all down in order before confirming them in the app.

The rules are the same as for any seed phrase. Xaman says the numbers are the only way to restore your account if something happens to your phone, that it has no copy and can’t recover them for you, and that you should never share them with anyone. For a walk-through of setting up the app, see the Xaman wallet setup guide.

How should you store a seed phrase?

Keep it on paper or another physical medium, offline, somewhere only you (and anyone you deliberately plan for) can reach. Ledger’s guidance is to never photograph or digitize your written copy, and never enter the phrase into a computer or smartphone. The only place it should go is back into the wallet it belongs to, on a device you control, during setup or a restore. A hardware wallet’s phrase should only ever be entered on the hardware device itself, never into a phone or computer app.

Bullrunners saw why in September 2026. More than 11.7 million XRP was drained from D’CENT app wallets, including some hardware wallet owners who had at some point typed their phrase into the phone app. See what happened to D’CENT app users.

What to avoid, and why:

Storage method	Problem
Photo on your phone	Synced to cloud backups and exposed to any app or person with access
Notes app, email or document	Readable by anyone who gets into the account
Password manager	Still a digital copy, exposed if that account is breached
Typing it into a “wallet checker” site	Hands it straight to whoever runs the site
One paper copy in the same drawer as the device	One theft or fire takes both

Who will ask for your seed phrase?

Only scammers. Ledger states it will never ask for your recovery phrase. Xaman says that if someone asks for your secret numbers, that person is trying to steal your funds. Its airdrop-scam guide adds that Xaman will never ask you to claim anything.

Requests usually come dressed as help: a “support agent” who replies to your public complaint, a “wallet validation” site, an airdrop claim page or an urgent message saying your account is at risk. The wording changes; the request doesn’t. Bullrunners covers the common versions in XRP scams explained.

Seed phrase safety checklist

1. Write it down by hand, in order, the moment your wallet shows it. Check each word or number twice.
2. Never create a digital copy: no photos, screenshots, notes, emails or cloud documents.
3. Make a second paper copy and keep it in a separate secure place.
4. Store the phrase away from the device, so one theft doesn’t take both.
5. Keep a passphrase, if you use one, separate from the seed words, with its own backup.
6. Never type it anywhere except the wallet it belongs to, during setup or recovery. Never type a hardware wallet’s phrase into a phone or computer.
7. Never share it, whoever asks and however official they look.
8. Send a small test transaction first whenever you move funds into a new wallet, before anything meaningful.
9. Plan for your family. Someone you trust should know how to find it if something happens to you. See crypto inheritance and self-custody.

What to check next

Write down every place your seed phrase has ever been typed, pasted or photographed. If that list isn’t empty, treat the phrase as exposed: set up a new wallet with a brand-new phrase and move your funds, starting with a small test. Then check you can physically find your paper backup today. If you can’t, that is the first thing to fix.

Sources

• Bitcoin BIPs: BIP-39, Mnemonic code for generating deterministic keys
• Ledger Academy: Passphrase, an advanced security feature
• Ledger Academy: Recovery sheet
• Xaman Help: How to create an XRPL account
• Xaman Help: Airdrop scams