A passphrase is often sold as a simple upgrade. It is really a trade: less risk of theft for more risk of loss. This guide helps you decide. It is part of our guide to the BIP39 passphrase. If this is new, read what the 25th word is.

The trade-off

BenefitCost
A found phrase is not enoughA forgotten passphrase loses your funds
A stolen device is saferThere is one more thing to back up
You can keep a decoy walletSetup and use are harder
You can store your phrase more freelyFamily recovery is harder

Who it suits

A passphrase suits you if all of these are true:

  • You already have a tested backup.
  • You hold enough that a found sheet of paper would be a serious loss.
  • You can store your phrase and passphrase in separate places.
  • You keep good records and handle details carefully.
  • Your family plan covers it.

Who should skip it

  • Beginners who are still learning.
  • People with small holdings.
  • Anyone who plans to keep it only in their head.
  • Anyone who has no safe second location.
  • People whose heirs would have no way of finding it.

Situations where it shines

  • Your words are at a bank or with family. A passphrase protects you if they are read.
  • A hardware wallet without a secure element. A passphrase protects you if someone extracts the seed.
  • Physical threats. A small decoy wallet may help in some situations. See physical threats.

Situations where it fails

  • Typing it into a fake site along with your phrase.
  • Choosing a weak one that can be cracked once your words are found.
  • Forgetting it after years of not using it.
  • Leaving it next to your phrase.

Alternatives

GoalOption
Remove the single point of failureMultisig
Split a backup safelyShamir
Protect against fireMetal backup

See multisig vs passphrase for a direct comparison.

If you decide to go ahead

  1. Choose a strong passphrase.
  2. Back it up separately.
  3. Test the full recovery with a small amount.
  4. Review it every year.