Safety
A multisig wallet requires several separate keys to approve a spend, commonly two of three. It removes the single point of failure in a normal wallet: no one key can move funds, and losing one key loses nothing. It also adds a second thing you must back up, the wallet descriptor, without which the keys alone cannot rebuild the wallet. Multisig is worth the complexity when a single seed phrase going missing or being found would change your life, and not before.
What it actually is
An ordinary wallet has one key. Whoever holds it can spend, and whoever loses it has lost everything. Every disaster in self custody traces back to that single point.
A multisig wallet splits that authority across several keys and sets a threshold. A two of three wallet has three keys and needs any two of them to approve a spend. A three of five needs any three. The keys are separate devices, usually in separate places, and no single one of them can do anything alone.
Choosing the threshold
| Setup | Keys needed to spend | Keys you can lose | Honest verdict |
|---|---|---|---|
| 2 of 2 | Both | None | Do not. It doubles your chance of permanent loss and gives you nothing in return. |
| 2 of 3 | Any two | Any one | The default for individuals. Enough redundancy to survive a loss, few enough parts to actually maintain. |
| 3 of 5 | Any three | Any two | For larger amounts or several people. More resilient, and noticeably more work every time you spend. |
| 1 of 2 | Either one | Either one | Not really multisig. Convenience, not security. Either key alone can empty it. |
For almost everybody reading this the answer is two of three, or nothing.
The backup nobody mentions
This is the part that turns a multisig into a loss, and it is skipped in most explanations.
With a normal wallet, the seed phrase is the whole backup. Twelve or twenty four words rebuild the wallet on any device, and that is the end of it.
With a multisig, the seed phrases are not enough. Each key knows its own half, but nothing in those words records that they belong to a two of three wallet, which other keys are involved, or how the addresses are built. That information lives in a separate file called the wallet descriptor, sometimes called the output descriptor or the wallet configuration. Without it, you can hold every seed phrase you own and still be unable to find your coins.
Three times multisig did not save anybody
It is worth knowing the shape of these before you decide, because they all rhyme.
| What happened | When | Why the extra keys did not help |
|---|---|---|
| Parity multisig freeze. Around 514,000 ETH across 587 wallets became permanently unspendable. | November 2017 | A shared library contract the wallets depended on was deleted by an outsider. Nothing was stolen and no key was compromised. The wallets simply stopped working, and complexity was the entire cause. |
| Radiant Capital lost about $53m from a three of eleven multisig. | October 2024 | Malware showed each signer a normal looking transaction in the interface while their hardware wallets were asked to sign something else. Three honest people approved three lies. Eleven keys made no difference. |
| Bybit lost about $1.46bn from a cold multisig. | February 2025 | The signing interface itself was compromised upstream, so every signer was shown the same false picture of what they were approving. The threshold was met by people who believed they were doing their jobs. |
The pattern is the same in all three. Multisig defends against one key being stolen. It does nothing against every signer being shown the same lie, and it adds machinery that can break on its own. That is an argument for verifying what you sign on the device screen rather than in the app, and for keeping the setup simple enough that you understand every part of it.
Whether you actually need one
Multisig is probably worth it
If more than one of these is true
- Losing the wallet would materially change your life
- You are holding for years, not trading weekly
- Somebody else needs to be able to reach the funds if you cannot
- You already keep a hardware wallet and a metal backup and want the next step
- The money belongs to more than one person
Stay with one key for now
If any of these are true
- You do not yet have a hardware wallet at all
- Your seed phrase is written on paper in one place
- You move funds most weeks
- You would not enjoy a yearly rehearsal of the recovery
- The amount is small enough that the setup cost outweighs it
The ways to actually do it
| Approach | What it costs | Who it suits |
|---|---|---|
| Do it yourself with open software. Sparrow, Nunchuk or Electrum coordinate the keys; the hardware wallets can be from different manufacturers on purpose. | Free, plus the hardware wallets themselves | People willing to read documentation, rehearse a recovery, and own the descriptor backup completely. |
| Collaborative custody. A company holds one key and helps you recover, but cannot spend alone because it never holds enough keys. | Unchained lists vaults at $250 per vault per year. Casa lists a three key membership at $250 a year and a five key membership at $2,100 a year. Read September 2026. | People who want the redundancy without being the only person who understands the setup. |
| Safe, for Ethereum and other EVM chains. A smart contract wallet where the threshold is enforced onchain. | Free to use. You pay gas to deploy it and gas on every transaction. | Anything onchain, and any group that needs several people to approve a spend. |
A note on the middle row: collaborative custody is not the same as an exchange holding your coins. In a two of three where the company has one key, it cannot move anything without you, and you can move everything without it using your other two keys. The service you are buying is support and a spare key, not custody.
If you decide to do it
Rehearse with nothing at stake
Build the wallet, send in a trivial amount, then wipe every device and recover the whole thing from your backups alone. If you cannot get the money back with the words and the descriptor in front of you, you have not finished setting it up.
Use different manufacturers
Two of the three keys on hardware from different companies means a flaw or a supply chain problem at one of them cannot reach your threshold.
Separate the keys physically
Three devices in one drawer is one device. Home, a safe deposit box and a trusted person is the usual shape. Consider what a fire, a burglary and a flood each reach.
Store the descriptor everywhere
It holds public keys only, so extra copies do not weaken it. A copy with each seed backup, one in your password manager and one with whoever handles your estate.
Verify on the device, not the screen
Every one of the failures above involved a signer trusting what a computer displayed. The address and the amount on the hardware wallet screen are the only ones that count.
Write it down for somebody else
A page explaining what this wallet is, where the keys live and what to do with them. See recovery planning.
Common questions
Is multisig the same as two factor authentication?
No. Two factor authentication protects a login to a company that holds your money. Multisig changes who can move the money itself, and there is no company involved. They solve different problems and you can want both.
Can I lose funds if one key is stolen?
Not in a two of three or three of five. The thief needs to reach the threshold. You should still treat one stolen key as an emergency and move the funds to a fresh wallet, because they only need one more.
What happens if I lose the descriptor but still have all the seed phrases?
Some software can rebuild it by trying common configurations, and if you remember the quorum and the address type there is a reasonable chance. That is a rescue operation, not a plan. Back up the descriptor.
Does multisig work for every coin?
Bitcoin has the most mature tooling. On Ethereum and other EVM chains it is done with a smart contract wallet such as Safe, which behaves differently and costs gas. Many other chains have partial support or none.
Is a passphrase a substitute?
It solves a different problem. A passphrase protects against somebody finding your written words. It does not give you redundancy, and it adds a way to lose everything. See the 25th word.
Can I use multisig for inheritance?
Yes, and it is one of the better reasons to. Giving a trusted person one key of three means they cannot spend on their own but can be part of a recovery. Read what happens to your crypto when you die first.
Where to go next
Get a second pair of eyes on your setup
A security session reviews what you hold, where it sits, what approvals are open and what would happen if your laptop were compromised tomorrow. Most people find at least one thing worth fixing.