What Is a Passphrase Wallet (the 25th Word)? Explained Simply

What Is a Passphrase Wallet?

Published 2026-08-15. Last updated 2026-08-15. Written by John Alewine, Crypto Guidance Inc.

A passphrase wallet (often called the 25th word) is an extra secret you type on top of the 12 or 24 BIP-39 words. The words alone open wallet A. The words plus the passphrase open wallet B, a completely different set of keys. There is no checksum on the passphrase. Typo it and you get a third, empty wallet, and the software will not warn you.

Who This Is For

A small set of people with a written passphrase stored as carefully as the steel, plus a family letter that says the visible phrase is a decoy. That is a high bar. For most households I work with, a passphrase is how coins become unrecoverable. If you wanted plausible deniability, say so out loud and then decide whether you will still remember the phrase in ten years.

How It Actually Works

The passphrase is not one of the 2048 BIP-39 words unless you chose one. It can be any string. Spaces matter. Capitals matter.
Hardware wallets offer it as an advanced feature. Each passphrase can be a hidden wallet on the same device. The seed card still looks complete without it.
This is not social recovery and not a multisig. It is a second password with no reset.

Risks I See in Sessions

Enabling it "because the YouTube guy said so," then forgetting whether a space was at the end. The restore looks fine. The balance is zero. There is no vendor to call.
Putting the passphrase on the same paper as the words. You just made a 25-word seed with extra steps, and you lost the deniability.
A family restore after a death that never mentions the hidden wallet. See the inheritance guide.

When It Matters

Only after a basic hardware setup works, a steel backup is tested, and you have a written reason. Default is off. The Security page is enough for almost everyone.