Which Trezor devices support SLIP-39 backups?

SLIP-39 backups are supported by Trezor Model T, Trezor Safe 3, and Trezor Safe 5.

Can I upgrade my existing BIP-39 wallet to SLIP-39 directly?

No. SLIP-39 is a different backup standard. To switch, you’ll need to create a new SLIP-39 wallet and transfer your funds to it.

Can I upgrade a SLIP-39 backup later?

Yes. If you start with a 20-word Single-Share backup, you can upgrade to a Multi-Share setup anytime using Trezor Suite. Your original backup will still work unless you choose to retire it.

Can I use a passphrase with BIP-39 and SLIP-39?

Yes, but it introduces a new single point of failure. If you lose or forget the passphrase, your wallet can’t be recovered, even with the correct backup. Make sure you write it down and don’t lose it.

What if Trezor stops making hardware wallets?

BIP-39 and SLIP-39 are open standards supported by multiple wallets. Even if Trezor were unavailable, you could recover your wallet using other compatible devices or software.

Is SLIP-39 compatible with multisig?

Yes. SLIP-39 can be used to securely back up one of the keys in a multisig wallet. If the original device is lost or unavailable, the key can be restored using the SLIP-39 shares and imported to a new device.

How many shares can I create with SLIP-39?

Up to 16 shares. More shares can offer more flexibility, but they’re also harder to keep track of.

What happens if I lose a SLIP-39 share?

As long as you still have the required number of shares (the threshold), you can recover your wallet. With fewer than the threshold, recovery is not possible — and no usable information about the wallet or keys can be extracted. If you believe one or more shares may have been compromised, it’s safest to create a new wallet and move your funds.

Why use Multi-Share instead of just splitting a regular backup myself?

SLIP-39 uses cryptography to split your backup securely. Any number of shares fewer than the threshold reveal nothing on their own. Manually splitting a BIP-39 phrase (e.g. writing half in one place, half in another) doesn’t offer the same protection and increases the risk of accidental loss or compromise.

What is the difference between a 12-word and a 24-word BIP-39 backup? Is 24 words safer?

A 24-word backup has more entropy, but a 12-word backup is already unguessable in practice. Even with billions of supercomputers, it would take longer than the age of the universe to brute-force.

What matters most isn’t the number of words — it’s keeping your backup safe, private, and offline.

Why does SLIP-39 use 20 words?

SLIP-39 uses 20 words because each share includes extra information — like group and threshold data — and a stronger checksum to detect errors. The longer format helps ensure each share is unique, verifiable, and secure.

Should I upgrade to SLIP-39?

If your BIP-39 backup is secure and works well for you, there’s no urgent need to switch. However, if you’re looking for enhanced security, flexibility, or worry about a single point of failure, SLIP-39 might be a better option.