Your seed phrase is not a password. Passwords can be reset. If you lose your seed phrase and lose access to your device, your funds are gone permanently. There is no account recovery. There is no support ticket. There is no company holding a backup copy.
This guide covers exactly how to back it up correctly — and the common mistakes that cause people to lose everything.
What your seed phrase actually is
A seed phrase — also called a recovery phrase, mnemonic, or backup phrase — is a sequence of 12 or 24 common English words generated when you create a new wallet. It looks something like this:
Example only — never use a seed phrase you saw written somewhere else.
These 12 words are not arbitrary. They are a human-readable encoding of a 128-bit random number, derived through the BIP-39 standard, from which your wallet mathematically generates every private key it will ever use. Anyone who has these 12 words can regenerate your wallet on any device, anywhere, at any time.
Step 1 — Write it down correctly
When Heldby (or any wallet) shows you your seed phrase, take these steps:
- Get a piece of paper and a pen. Do not type it anywhere. Do not take a photo. Write it physically.
- Write every word in order, numbered. The order matters — the same 12 words in a different sequence is a completely different wallet.
- Write clearly. Distinguish between similar-looking words (e.g., "slim" vs "slum") and between similar letters (e.g., "l" vs "1", "O" vs "0").
- Double-check each word against what the wallet shows. A single wrong word can mean your backup is useless.
Do this before you deposit anything
The time to verify your backup is before your wallet holds real value, not after. Write it down, verify it, store it — then fund your wallet.
Step 2 — Store it safely
Where you store your seed phrase is as important as writing it correctly. The threat model has two sides: loss (fire, flood, you forget where it is) and theft (someone finds it).
Good storage options:
- Fireproof safe at home. Protects against fire and provides some theft deterrence. Make sure someone trusted knows it exists.
- Bank safety deposit box. Excellent physical security, protected against both theft and natural disaster. Access depends on banking hours.
- Metal backup plate. Stainless steel or titanium "crypto steel" products let you stamp or engrave your seed phrase. Survives fire, flood, and corrosion that paper cannot.
- Second physical copy in a different location. If one location is destroyed, the other survives. Useful if you use a safety deposit box as the primary.
What to avoid:
- Photos on your phone — iCloud/Google Photos sync means it leaves your device immediately.
- Notes apps, Google Docs, Notion, or any cloud-connected app — if the service is breached, your phrase is exposed.
- Email — email is not encrypted in transit or at rest on most services.
- Password managers — a reasonable secondary record but not your primary backup; if the password manager is compromised, so is your wallet.
- Anywhere your cleaner, house guests, or family members might find it unintentionally.
Step 3 — Verify your backup before you need it
Writing down your seed phrase is necessary. It is not sufficient. You also need to verify that what you wrote is correct and that you can read it clearly months or years later.
The worst time to discover your backup is wrong is when you need it — when your device is lost, broken, or stolen.
Heldby runs a 30-day backup test that asks you to confirm 3 randomly selected words from your phrase. This is not a security theatre exercise. It catches two real failure modes:
- Transcription errors — you wrote word 7 incorrectly when you first backed up.
- Legibility decay — ink fades, paper degrades, your handwriting was ambiguous. A test a year later catches this before it's a crisis.
How the 30-day test works in Heldby
Every 30 days, Heldby asks you to enter words 4, 9, and 11 of your phrase (for example). Get them right and your backup is confirmed intact. Get one wrong and you need to locate your written copy and check it immediately — before anything happens to your device.
What happens if you lose it
If you still have your device: you can view your seed phrase in Heldby under Settings → Backup. You will need your PIN. Write it down now.
If you have lost both your device and your backup: your wallet is unrecoverable. The funds remain on the Ethereum blockchain permanently, but no one — not Heldby, not Ethereum, not anyone — can access them without the seed phrase.
This is not a flaw in the design. It is the defining property of self-custody. You are the bank. The responsibility that comes with that is real — but so is the security. No company can freeze your account, no government can seize it, no server breach can drain it.
One more thing: don't share it with anyone
No legitimate wallet, exchange, customer support agent, or protocol will ever ask for your seed phrase. Not to "verify" your wallet. Not to "restore" it. Not to "synchronise" it. If anyone asks for your seed phrase, they are attempting to steal it. The end.