Multisig Wallet: More Security Through Several Keys

A multisig wallet needs several keys instead of one for every payment. The usual setup is "2 of 3": there are three keys on three devices in three places, and two of them sign. If one key is lost or stolen, your bitcoin are neither gone nor in someone else's hands. The price: more devices, more backups, more care.

The problem: everything depends on one slip of paper

With a hardware wallet you have already done a lot right. Your key never leaves the device, and malware on your computer can't send anything without your confirmation. The guide to storing bitcoin safely explains this in detail.

One weak point remains: the seed phrase. The 12 or 24 words are your entire wealth. If someone finds them during a burglary, a move or in your bank safe deposit box, the coins are gone. If your house burns down and the backup was there, the same.

The larger the holdings, the more this one point weighs. Multisig solves exactly this problem: there is no longer a single point on which everything depends.

How a multisig wallet works

"Multisig" stands for multi-signature, several signatures. The rule is built into Bitcoin itself, not held by a company: coins on a multisig address can only be moved if enough of the keys involved sign. Every Bitcoin node in the world checks this.

It is written as "M of N": there are N keys, and M of them must sign.

• 2 of 3: three keys, two sign. The standard for private individuals.
• 3 of 5: five keys, three sign. More for companies, foundations or large family fortunes.

Each key is a perfectly normal wallet with its own seed phrase, usually on its own hardware wallet. Only a piece of wallet software, the coordinator, combines the three into a shared wallet. It generates the addresses, prepares payments and collects the signatures.

Why 2 of 3 is the standard

2 of 3 forgives exactly one mistake, in both directions:

• A key is stolen: the thief only has one of the two needed. You move the coins to a new wallet with the other two.
• A key is lost: you still have two. With them you can keep paying and replace the lost key.

Other splits shift the balance, mostly for the worse:

What you need to back up with multisig

This is where most mistakes happen. With a simple wallet, the seed phrase is enough to restore everything. With multisig it isn't.

You need two things:

1. Enough seeds: for 2 of 3, at least two of the three seed phrases.
2. The wallet descriptor: a text file or QR code that records which three keys belong together and under which rule. Technically it is called an "output descriptor"; some programs call it the wallet configuration or wallet backup.

Why the descriptor is so important: from two seeds, only two of the three public keys can be calculated. But the wallet needs all three for the addresses. If the descriptor is missing and the third seed is lost, no software will find your coins any more.

The descriptor is not secret, but it is private. So don't hand it out lightly: with it, someone can trace your entire holdings and all your payments.

Setting up a multisig wallet: step by step

This is how a 2-of-3 wallet is created, with three hardware wallets and a coordinator on your computer:

1. Choose a coordinator. Widely used programs that support bitcoin multisig with hardware wallets include Sparrow, Nunchuk, Electrum and Bitcoin Core. Only download them from the official site.
2. Set up three devices. Each hardware wallet gets its own seed phrase and PIN. Copy each phrase neatly and label it, for example "Key A". Which devices are suitable is shown in the hardware wallet comparison.
3. Use devices from different manufacturers. If one manufacturer has a bug, it only affects one of your keys.
4. Combine the wallet. The coordinator reads the public key (xpub) from each device and creates the multisig wallet from them. Many devices then also register the wallet themselves so they can verify addresses on their own.
5. Export the descriptor. Save the wallet descriptor, print it and put it with each seed.
6. Check the address on the devices. Display the first receiving address on at least one device and compare it with the screen. Only then do you know the computer hasn't slipped in someone else's address.
7. Practise recovery. Send a small amount, delete the wallet in the coordinator and restore it from the descriptor and the devices. Then spend the small amount again with two devices.
8. Only then the rest. Once the test payment and recovery have worked, transfer your holdings, first a small part, then the rest.

Where the three keys belong

Three keys in the same cupboard achieve almost nothing: a burglar or a fire hits them all. The benefit of multisig only comes from separation.

A proven pattern for 2 of 3:

• Key A at your home, ready for payments.
• Key B in a second place you can easily reach, for example in a bank safe deposit box or at the office.
• Key C far away, for example with a trusted person in another city, sealed, with the wallet descriptor.

The trusted person alone can't move anything. A burglar in your home finds only one key. To pay you need A and B, and you can reach both in one day. The same separation also protects you if someone puts you under pressure: at home you can't pay on your own at all. More on this in the article Discretion and physical security.

Self-custody or with a service?

There are services for collaborative custody: you hold two keys, the service one. On its own it can't move anything. If you lose a key, it co-signs after verifying your identity, and some help with inheritance.

That is convenient, but it brings in a company that knows your addresses, charges fees and can go bust. So it is important that you can reach your coins at any time without the service: with your two keys and the wallet descriptor you must be able to pay from any compatible wallet. What happens when you rely entirely on a company is shown by the crypto exchange collapses from Mt. Gox to FTX.

Multisig, passphrase or a simple hardware wallet?

Multisig isn't the only way to secure the seed phrase. The passphrase, often called the "25th word", is an additional password without which the seed only opens an empty wallet. It is cheaper and simpler, but again has a single point of failure: if you forget it, the coins are gone.

Another method of splitting seeds into parts (Shamir, SLIP39) is often confused with multisig. With it, the signing key is put back together in one place. With multisig it never exists as a whole; each device signs for itself.

When a multisig wallet is worth it

There is no fixed threshold. A good question is: would a single mistake, a burglary, a fire or a lost slip of paper change your life? Then multisig is worth considering.

The second question is just as important: do you understand the setup well enough to still restore it in five years? A multisig wallet you no longer understand is riskier than a well-secured simple wallet.

What your holdings are worth today in euros, francs and sats you can work out here:

How much bitcoin you want to hold in the long run and what that means for your custody you can play through in My Goal.

The most common mistakes with multisig

• Wallet descriptor not backed up. The most expensive mistake. Two seeds without the descriptor are not enough if the third is missing.
• All keys in one place. Then multisig protects neither against burglary nor against fire.
• Choosing 2 of 2. One lost device and everything is gone.
• Never practised. If you have never tried the recovery, you only notice mistakes when it matters.
• Signing blindly. A manipulated computer can display a false address. In February 2025 the exchange Bybit lost crypto assets worth about $1.5 billion from a multisig wallet because the signers confirmed a manipulated payment. Always check on the device.
• No plan for the family. Without instructions, nobody will work out which three devices and which file belong together.

Multisig and inheritance: a plan someone understands

Multisig can even make inheritance easier if you plan it. A trusted person or a notary keeps one key and the wallet descriptor, and your family knows where a second one is. During your lifetime nobody can pay alone; in an emergency your heirs get to two keys.

This needs written instructions that someone without specialist knowledge understands: which software, where which devices and seeds are, where the descriptor is and whom to ask for help. They say where the keys are, not what the keys are. How to raise the subject is shown in the article How to talk to your partner and family about Bitcoin.

You learn keys, seeds and backups step by step in the Academy, stage 2: understand and secure. All articles on the topic are in Security & Custody.