A seed phrase (also called a recovery phrase or mnemonic) is a list of 12 or 24 ordinary words that a non-custodial crypto wallet generates when you create it. Those words are a human-readable version of the master key behind every address in your wallet. Anyone who has your seed phrase can take your crypto, and if you lose it along with your device, nobody can recover your funds.
That's why the seed phrase is the single most important thing to understand about self-custody. This guide explains how it works, how to store it, and how to spot the scams built to steal it.
How a seed phrase works
Most wallets follow a standard called BIP-39. It defines a list of 2,048 words. When you create a wallet:
- The wallet generates a large random number on your device.
- That number is encoded as 12 or 24 words from the BIP-39 list.
- The words are used to derive a master key, which in turn generates all your private keys and addresses, across Bitcoin, Ethereum, Tron, Solana and other networks.
Because the process is standardized, the same seed phrase can restore your wallet in any compatible wallet app. Your crypto isn't stored "in" the phrase. It's on the blockchain. The phrase is simply the master key that proves ownership.
12 words vs 24 words
A 12-word phrase already has 128 bits of randomness, far beyond what any computer can brute-force. A 24-word phrase has 256 bits. Both are considered secure. The real-world risk is never someone guessing your words. It's someone seeing, photographing or phishing them.
Seed phrase vs private key vs password
| What it is | What it controls | |
|---|---|---|
| Seed phrase | 12–24 words | Every account and address in the wallet |
| Private key | A long string for one address | One address on one network |
| App password / PIN | Unlocks the app on your phone | Only the app on that device, not your funds |
Forgetting your app PIN is usually fine. You can reinstall the app and restore from the seed phrase. Losing the seed phrase is not fine.
Do custodial wallets have a seed phrase?
No, not one you hold. In a custodial wallet the provider manages the keys, and you recover access through the provider's account recovery process. That's the main convenience trade-off covered in custodial vs non-custodial wallet.
Virtex Wallet offers both. In non-custodial mode you get a seed phrase and full self-custody. In custodial mode there's no seed phrase to manage. (Custodial mode isn't available in the EEA, the UK or the USA.)
How to back up your seed phrase: the right way
Do:
- Write it on paper, by hand, in the exact order, with the words numbered.
- Check every word against what the app shows. Many wallets ask you to confirm a few words after you write them down. Don't skip that step.
- Make two copies and store them in separate secure places (for example a home safe and a trusted family location).
- Consider a metal backup (steel plates or engraved tiles) for fire and water resistance if you hold significant amounts.
- Plan for inheritance. Think about how a trusted person could access funds if something happened to you, without exposing the phrase today.
Don't:
- ❌ Take a screenshot or photo. Phones sync photos to the cloud, and malware scans galleries.
- ❌ Store it in notes apps, email, cloud drives or password-protected documents online.
- ❌ Type it into any website, ever.
- ❌ Share it with anyone, including "support staff". No legitimate wallet or exchange will ever ask for it.
- ❌ Split the words across chats or messages.
Seed phrase scams to watch for
Almost every self-custody loss comes from one of these:
- Fake support. You post a question on X, Telegram or Discord, and a "support agent" DMs you asking for your phrase to "sync" or "validate" your wallet. Real support never asks.
- Fake wallet apps. Clones of real wallets that steal any phrase you import. Install only from Google Play or the wallet's official website. More tips in our Android wallet guide.
- Phishing sites. Pages that look like a wallet or dApp and ask you to "restore your wallet" to claim an airdrop.
- "Wallet validation" emails. Messages saying your wallet will be suspended unless you verify your phrase. Self-custody wallets can't be suspended.
- Shared seed phrase "gifts". Someone shares a phrase to a wallet holding crypto and asks for help withdrawing. It's a trap designed to make you send fees.
The one rule: if anyone or anything asks for your seed phrase, it's a scam.
What to do if your seed phrase is exposed
If you think someone has seen your phrase, even partly:
- Create a brand-new wallet with a new seed phrase, and back it up properly.
- Immediately move all funds from the old wallet to the new one. Remember you'll need a little of each network's coin for fees.
- Stop using the old wallet entirely.
Changing your app PIN does nothing here, because the phrase itself is compromised.
How to restore a wallet from a seed phrase
- Install the wallet app from an official source.
- Choose Import / Restore wallet, not "Create".
- Enter the words in order.
- The wallet re-derives your addresses. Balances appear once it checks the blockchain. If a token or network doesn't show, make sure that network is enabled.
Common questions
Can someone guess my seed phrase? Not realistically. The number of possible 12-word combinations is astronomically large. Theft happens through exposure, not guessing.
Can I change my seed phrase? Not for an existing wallet. Instead, create a new wallet and move your funds to it.
Is a passphrase the same as a seed phrase? No. Some wallets support an optional extra "passphrase" (sometimes called a 25th word) that creates a different set of accounts. It adds security but must also be backed up.
What if I lose my phone but have my seed phrase? You're fine. Install the wallet on a new device and restore with the phrase.
What if I lose my seed phrase but still have my phone? Open the wallet now and back up a new copy of the phrase if the app allows it, or move your funds to a new wallet whose phrase you back up properly.
Ready for self-custody, or prefer the easy-recovery option? Get Virtex Wallet on Google Play and choose the mode that fits you. This article is general information, not financial advice.