Passphrase FAQ: What every passphrase user should know

The passphrase is a sharp tool. Used carefully, it adds real security to your wallet. Used carelessly, it's one of the fastest ways to lose access to your own crypto.

This FAQ covers the questions we hear most often.

1. What is a passphrase and how does it work?

A passphrase is an optional string of characters that you add on top of your wallet backup. Together, they generate a completely separate wallet with its own addresses, balances, and transaction history.

Think of it this way:

• Wallet backup alone = your standard wallet
• Wallet backup + passphrase = a different wallet entirely

Every unique passphrase produces a unique wallet. There is no limit to how many you can create. Every single one is valid, which means every typo is also valid.

If you enter "MyPassphrase" instead of "mypassphrase," you'll open a different (empty) wallet with no error message. The device has no way to tell you it's wrong because, technically, it isn't.

A single character difference creates a completely separate wallet, and if you can't reproduce the exact passphrase, you can't access the funds.

2. Do I need a passphrase?

Most users don't. If you're using a Trezor and want to strengthen your backup security, you're usually better off with SLIP39 multi-share backup than with a passphrase.

SLIP39 lets you split your backup into shares (for example, 2-of-3) so that no single share can compromise your wallet, and you can lose one share without losing access. Before SLIP39 existed, the passphrase was one of the few ways to add protection beyond a single backup. Now that you can split your backup, there's a simpler and safer option available for most situations.

A passphrase adds a second secret that is equally necessary to access your wallet. That means if you lose either your wallet backup or your passphrase, your funds are gone. In security terms, this is called a single point of failure: any one thing whose loss causes total failure. A passphrase doesn't remove single points of failure from your setup. It adds one.

That said, if you're an advanced user with a specific security scenario in mind, a passphrase may provide real value. Some users have particular reasons for needing a separate wallet tied to the same backup, and for them the tradeoff makes sense.

A passphrase is worth using if you understand the risks, generate it with real randomness, and commit to writing it down and testing it. If any of that feels uncertain, SLIP39 is the better starting point.

3. What happens if I forget my passphrase?

You lose access to the wallet and everything in it.

Your Trezor device does not store your passphrase, and Trezor Suite doesn't keep it either. There is no recovery option, reset button, or support ticket that can fix this.

If you lose your passphrase, your only path is to try every variation you can think of: different capitalizations, with and without spaces, different special characters, common typos.

4. Should I write down my passphrase?

Absolutely. Write it down on paper or metal, something physical and durable. Do it the moment you create it.

People skip this step because they're confident they'll remember. But your passphrase is a string of characters you might type once a month or even less frequently. Human memory is far less reliable than it feels, especially for information you don't actively use. A passphrase you created weeks or months ago and haven't thought about since is exactly the kind of detail your brain lets go.

Here's what to do:

• Write the passphrase exactly as you typed it. Capital letters, lowercase letters, spaces, special characters. Every detail matters. "Hello World" and "hello world" open completely different wallets.
• Avoid ambiguous characters when choosing your passphrase. For instance, lowercase L (l), uppercase I (I), the number 1, and the number 0 versus uppercase O are easy to confuse when writing by hand. If you can, avoid them entirely.
• Along with your passphrase, write down the last 5 characters of the first receive address in your passphrase wallet's default account. This gives you a quick way to verify you're in the right wallet later. If you use wallet software that displays the wallet fingerprint (an 8-digit hex identifier), write that down instead. It's an even more reliable check.
• Make copies if you need to. Store them in different secure locations. The same rules that apply to your wallet backup apply here: no photos, no cloud storage, no digital copies.
• If your concern is someone finding both together, keep it separate from your wallet backup. The tradeoff is that you now have two things to keep track of in two places.

Can you try to memorize it too? Sure. But treat that as a bonus, never as your only backup.

Test your passphrase before sending significant funds. Create the passphrase wallet, send a small amount, close the wallet, re-enter the passphrase from what you wrote down, and confirm the funds are there. Do this every time you create a new passphrase wallet.

5. Where does the passphrase come from?

You create it yourself. Unlike your wallet backup, which your Trezor generates using hardware randomness, the passphrase is entirely your responsibility to choose, enter, and protect.

This means the security of your passphrase depends on how you create it. A well-chosen passphrase can be extremely strong. A poorly chosen one can be cracked in minutes or even seconds. The next question goes deeper into what "strong" actually means.

6. Is my passphrase strong enough?

The strength of a passphrase comes down to entropy, which is a measure of randomness. The more random your passphrase is, the harder it is for anyone to guess, including someone with specialized tools and your wallet backup in hand.

Entropy is measured in bits. Each additional bit doubles the number of possible combinations. A passphrase with 50 bits of entropy has about a quadrillion possible combinations. One with 77 bits has billions of times more than that.

The catch is that entropy only counts if the randomness is genuine. A passphrase you chose because it felt random to you almost certainly has far less entropy than one generated by dice rolls or a password manager. Humans follow patterns (favorite words, meaningful dates, common substitutions) and attackers know this.

If someone has your wallet backup and suspects you're using a passphrase, they can use cracking tools to work through candidates systematically. These tools don't just try random characters one by one. They use smarter strategies:

• Dictionary attacks test common words, phrases, and combinations from published word lists.
• Leaked password databases contain billions of real passwords people have actually used. Attackers test these against your passphrase.
• Pattern-based guessing tries common substitutions (@ for a, 3 for e), keyboard patterns, and capitalization habits.
• Targeted guessing uses personal information like names, birthdays, pet names, and favorite phrases that an attacker may know or find online.

A pure brute-force attack (trying every possible character combination) hits practical limits around 5–6 characters. Beyond that, attackers rely on the methods above. Security researcher Ryan Castellucci demonstrated at DEFCON how efficiently these techniques work against real-world passphrases.

Using the Diceware wordlist as a benchmark, each randomly selected word adds about 12.9 bits of entropy:

• 4 random Diceware words (~51 bits of entropy): Crackable with a serious budget and current hardware. Could cost as little as a few thousand dollars.
• 6 random Diceware words (~77 bits): Well beyond practical brute-force range. This is a strong passphrase.
• A random 10-character string using mixed case, numbers, and symbols (~65 bits): Strong against brute force, but harder to write down without errors.

For comparison, a passphrase like "purple2024!" follows patterns that cracking tools check early: dictionary word, year, common punctuation. Its effective entropy is far lower than its character count suggests. Even a very long passphrase can be guessed in seconds if it follows predictable patterns instead of using real randomness.

There are two practical ways to generate a passphrase with genuine randomness:

• Roll physical dice and pick words from a published wordlist like the EFF Diceware list. This is fully offline and requires no software at all.
• Use a password manager's built-in random generator. Tools like Bitwarden, KeePass, or 1Password use cryptographic randomness on your device to produce strong passphrases.

Both produce passphrases that are far stronger than anything a human brain can come up with.

What doesn't count as random:

• Words or phrases you thought of yourself
• Song lyrics, book quotes, or movie lines
• Looking at objects around the room and naming them
• Keyboard mashing or "random" typing
• Words in a foreign language, even an obscure one.
• Personal dates, names, or meaningful numbers
• Combining any of the above and scrambling, cutting, or substituting characters

All of these follow patterns that cracking tools are built to exploit. Even if the result feels unpredictable to you, the search space is dramatically smaller than you'd expect.

Here's the tension at the heart of passphrases: your passphrase might not be strong enough to stop a determined attacker who has your wallet backup and enough time. But it will absolutely be strong enough to lock you out permanently if you get it wrong or lose it.

A strong passphrase requires genuine randomness. If you chose yours without dice or a random generator, it's likely weaker than you think.

7. Can I use my passphrase with wallets other than Trezor?

Yes. Passphrases are part of the BIP39 and SLIP39 standards, both created by Trezor and widely adopted across the industry.

The same wallet backup combined with the same passphrase will generate the same wallet and the same addresses in any compatible software. Your funds are secured by open standards, not locked to a single vendor.

If you're using another wallet that supports BIP39 or SLIP39, it almost certainly supports passphrases as well. Look for it in the advanced settings or check the wallet's documentation.

8. What if I lose my Trezor device?

You can restore your wallet on a new Trezor. But you'll need two things: your wallet backup AND the exact passphrase.

The passphrase adds a second requirement beyond your wallet backup for restoring access. If you have both, buy a new Trezor, import your wallet backup, enable the passphrase feature, and enter the same passphrase. You'll see the same wallet with the same funds.

If you have the backup but have lost the passphrase, see question #3.

9. Should I use a passphrase to create a new account?

You don't need a passphrase for that. Trezor Suite and most other wallets let you create multiple accounts within your standard wallet backup. Click + Add account and you'll get a fresh set of addresses.

Creating a separate account is simple, free, and doesn't introduce new risks. If all you need is another Bitcoin or Ethereum account, use the account feature instead.

10. Should I share my passphrase with anyone?

Treat your passphrase like a part of your wallet backup. Anyone who has both can access your funds.

If you're planning for inheritance or want someone to access your crypto in an emergency, share it with a trusted person. Make sure they know what the passphrase is, where the wallet backup is stored, and how to use both together. Consider a written guide stored with the passphrase that explains the steps.

Without this kind of planning, a passphrase-protected wallet becomes permanently inaccessible if something happens to you. This isn't optional for long-term holders.

Conclusion

A passphrase creates a separate wallet tied to your existing wallet backup. It's a powerful security tool for experienced users.

If you choose to use a passphrase: write it down, test it, and store it as carefully as your wallet backup. Consider whether SLIP39 multi-share backup might achieve your goals with fewer risks.