TL;DR
Your Trezor, BitBox02 or Ledger can be one of the three keys, usually with the seed it already has. The multisig uses a different derivation path, so the old wallet and the vault stay separate. But that one seed can still spend the old wallet on its own, so empty it once the vault works. Use a fresh seed if the old one was ever exposed or isn’t in a format that fits.
Can my existing device be one of the three keys?
Yes. A multisig doesn’t need a seed made for it. Sparrow takes a public key from each device on the multisig path m/48’/0’/0’/2′. Your current single-sig wallet sits on a different path (usually m/84’/0’/0′ for bc1q addresses). Both come from the same seed, but they’re separate wallets. The multisig xpub doesn’t reveal your old addresses and the old xpub doesn’t reveal the vault. See derivation path explained.
Three rules don’t change: three different makers, so your two new devices are from the other two brands; buy them from the maker or Amazon.com itself (why not resellers); and do the tamper check.
Keep the seed, or start fresh?
Keeping it is fine if the seed passes every check below. If one fails, give that key a fresh seed.
- The words have never been typed, photographed or stored digitally, and nobody else has seen them.
- The device came from the maker or Amazon.com itself, new and sealed. Not second-hand, not from a reseller.
- Trezor: the backup is 24 words (BIP39), not the 20-word default. A 20-word SLIP39 backup can’t be restored on your other devices, and it can’t be converted.
- BitBox02: you have the 24 words written down, not only the microSD card.
- Ledger: you never subscribed to Ledger Recover, so no copy of your seed sits with other companies.
- No passphrase of its own that differs from what you’ll use on the other two. If you use a passphrase, the site advice is the same one on all three devices.
A BitBox02 that only has the microSD backup can still pass: it can show its recovery words on its own screen (Settings → Manage device → Backups → Show recovery words). Write them down, put them on metal in step 5 and check them against the device. After that, destroy the microSD card: anyone who finds it can restore your wallet.
The one trade-off of keeping the seed
That seed now does two jobs. It’s one of three keys to the vault, and it’s still the only key to the old wallet. Whoever finds that one backup can’t touch the vault, but can empty anything left in the old wallet. So once the vault works, move everything out of the old wallet and stop using it. Delete it from any saved withdrawal addresses at exchanges too, so nothing lands there by habit.
Want the old device for spending money instead? That’s a fine setup: keep it as your single-sig wallet and buy three new devices from three makers for the vault.
Steps
- Run the checks above and decide: keep the seed, or start fresh later.
- Buy the two other devices, from the two brands you don’t have yet (step 1).
- Prepare the signing laptop and install Sparrow.
- Update the firmware on your old device. Ledger: Bitcoin app 2.1 or newer. Set up the two new ones as in step 4. The old device keeps its seed, so skip “create a new wallet” for that one.
- Put all three seeds on metal and check each against its device (step 5). Your old paper backup counts as paper: once the plate checks out, destroy it.
- Build the vault, back up the descriptor, verify an address, send a test and rehearse a recovery: steps 6 to 10.
- In the old device’s own app (Trezor Suite, BitBoxApp or Ledger Wallet), send a small amount to an address you verified on the BitBox02 or Ledger. Check what you sign on the device screen. Wait until Sparrow shows it confirmed.
- Send the rest. The old wallet is now empty.
Coins still on an exchange? Move them as in exchange to multisig.
If you want a fresh seed on the same device
A device holds one seed at a time. Resetting it wipes the old wallet from the device, and then only your old backup can open it. So never reset a device that still guards coins. The safe order:
- Build the vault with the old seed and move everything in, as above.
- Reset the old device, create a new 24-word seed and put it on metal.
- Build a second vault from the two untouched keys plus the new one, back it up, test it, then send everything over, signing with the two keys you kept. A seed backup was seen or taken describes the same move step by step.
That costs two rounds of fees and a second descriptor backup. If the old seed was only fine but not perfect, keeping it is usually the better deal. If it was really exposed, rotate it.
Bought from a reseller or second-hand?
Then a fresh seed isn’t enough. Don’t use that device in your vault at all. After the October 2026 reseller incident, Ledger advised buyers who had already set up such a device to consider moving their funds to a new device with a new seed. See the alert.
Common mistakes
- Buying a second device of the brand you already own.
- Resetting the old device before its coins are out.
- Typing the old seed into Sparrow or a website to “import” it. Never: the multisig takes only public keys from the device.
- Leaving coins in the old wallet and keeping a saved exchange address that points to it.
- Keeping the Trezor’s 20-word backup because “it already works”.