Bitcoin multisig explained: a 2-of-3 setup for normal people
A 2-of-3 multisig keeps three keys in three places and lets any two of them spend, so no single mistake can cost you everything.
A multisig wallet needs more than one key to spend. In a 2-of-3 setup, three hardware wallets each hold one key, and any two of them can sign a transaction. Lose one key, or have one stolen, and your bitcoin is still safe and spendable. To recover the wallet you need two seed phrases plus the wallet descriptor, a file that lists all three public keys.
Disclosure: I work at Blockstream, the company that makes the Jade wallets mentioned here. I joined after many years as a satisfied user. There are no affiliate links on this site.
How multisig works
A normal single-signature wallet locks your bitcoin to one key. Whoever holds that key, or its seed phrase, can spend. A multisig wallet locks your bitcoin to a rule instead: "any 2 of these 3 keys must sign." The rule is written into the Bitcoin output itself, so every node on the network enforces it. No company, server, or app has to stay honest for it to work.
The standard way to describe that rule is an output descriptor. BIP383 defines two descriptor functions, multi and sortedmulti, which take a threshold and a list of public keys and produce a multisig output script. In the native SegWit (P2WSH) form, a single multisig can hold up to 20 keys, far more than you will need.
Each key in a 2-of-3 lives on its own hardware wallet with its own seed phrase. When you spend, your software builds an unsigned transaction (a PSBT, defined in BIP174), and you pass it to two of the devices to sign. Once two signatures are on it, you broadcast it.
Why I recommend 2-of-3
Every multisig setup trades protection against theft for protection against loss.
| Setup | A thief needs | You can lose | Verdict |
|---|---|---|---|
| 1-of-1 (single-sig) | 1 seed phrase | The device, if the seed phrase survives | Fine for most balances |
| 2-of-2 | Both seeds | Nothing: lose either key and the funds are stuck forever | Avoid |
| 2-of-3 | Any 2 seeds | Any 1 key | The default I recommend |
| 3-of-5 | Any 3 seeds | Any 2 keys | More places to manage, for large holdings or organizations |
A 2-of-3 removes the single point of failure without adding much complexity. A burglar who finds one device and one seed phrase in your house cannot spend, and a fire that destroys one backup costs you nothing. Keep the three keys in three different locations, or the setup only protects you on paper.
Multisig vs MPC
MPC (multi-party computation) wallets also split signing power between several parties, but they do it off the blockchain. The parties hold shares of one key and cooperate to produce one ordinary signature. Threshold schemes such as FROST produce signatures that verify as if a single signer made them.
| Multisig | MPC | |
|---|---|---|
| Where the rule lives | In the Bitcoin output, enforced by every node | In the software that coordinates the key shares |
| Recovery | Any wallet that reads the descriptor and holds enough seeds | The scheme and tools used to create the shares |
| Standards | Public BIPs (descriptors, PSBT) | Varies by vendor |
| On-chain footprint | Larger transactions, visible as multisig when spent | Looks like a single-signature spend |
I pick multisig for personal savings. The rules are part of Bitcoin, the formats are public, and you can rebuild the wallet in a different app years from now with nothing but your seeds and the descriptor.
What you need
- Three hardware wallets that support multisig. Sparrow's own best-practice guide recommends devices from different vendors, so one firmware bug cannot touch all three keys. Jade can register up to eight multisig wallets and verify their receive addresses. BitBox02 lists single-sig and multisig support with Sparrow, Nunchuk, Electrum, and Specter. SeedSigner exports multisig xpubs and verifies multisig change outputs.
- A coordinator app that builds the wallet and the transactions. Sparrow on desktop is the one I recommend. Nunchuk runs on iOS, Android, and desktop, and its free plan includes DIY multisig wallets. Electrum also supports multisig.
- Three seed phrase backups, ideally on metal (see seed storage).
- Three locations you trust: your home, a safe deposit box, a relative's house, or an office safe.
How to set up a 2-of-3 in Sparrow
Set up all three hardware wallets first, each with its own new seed phrase, and back up each seed before you continue.
- 1In Sparrow, choose File > New Wallet and name it.
- 2Set Policy Type to Multi Signature HD. Set the Cosigners slider to 2 of 3. Leave the script type on Native Segwit (P2WSH), the default.
- 3Sparrow opens one keystore tab per key. In each tab, add a device with Connected Hardware Wallet (USB) or Airgapped Hardware Wallet (QR or SD card).
- 4Click Apply and set a password for the wallet file.
- 5Sparrow now shows a Backup Multisig Wallet? dialog with the full output descriptor. Click Save PDF and print it: this is the backup covered in the next section.
- 6Register the wallet on any device that supports it, then open the Receive tab and check that the first address matches on each device's screen.
- 7Send a small amount in, then spend it back out with two of the devices signing before you move real savings.
Back up the descriptor
After you create a multisig, Sparrow warns that to restore the wallet, you need at least two seeds and ALL of the xpubs. Every multisig address is built from all three public keys. With two seeds and no record of the third public key, no wallet can work out which addresses hold your coins, even though two signatures would be enough to spend them.
The descriptor solves this: it contains the threshold, the script type, and all three xpubs with their fingerprints and derivation paths. Unchained calls the same thing a wallet configuration file. Nunchuk exports it as a BSMS file.
Store a copy of the descriptor with each seed phrase backup. It cannot spend anything, but it reveals your full balance and history to whoever reads it, so keep it out of email and cloud storage.
Doing it yourself vs collaborative custody
If running three devices alone feels like too much, collaborative custody services set up a 2-of-3 where you hold two keys and the company holds the third. Unchained charges $250 a year per vault and says it "can never move your bitcoin" on its own key. Nunchuk's Iron Hand plan is $120 a year for a 2-of-3 assisted wallet. Bitkey sells a $250 device for a 2-of-3 where you hold two keys and the third exists for recovery.
You give up some privacy, since the company knows your addresses, and you pay every year. You gain a partner who can help you recover if you lose a key. For a full comparison of these services and their inheritance features, see my inheritance page.
Frequently asked questions
What is a multisig wallet?
A multisig wallet requires signatures from more than one key to spend. A 2-of-3 multisig has three keys, and any two of them can approve a transaction. The rule is enforced by the Bitcoin network itself.
What is the difference between MPC and multisig?
Multisig puts the "2 of 3 keys" rule into the Bitcoin output, where every node enforces it. MPC splits one key into shares that cooperate off-chain to make a single signature. Multisig recovery depends only on public standards. MPC recovery depends on the scheme and software that created the shares.
Is multisig safer than a single hardware wallet?
It removes the single point of failure. A stolen seed phrase or a destroyed backup no longer means losing your bitcoin. It also adds more backups to manage, so it is only safer if you keep the keys in separate places and back up the descriptor.
Can I mix hardware wallet brands in one multisig?
Yes, and you should. Multisig uses standard descriptors and PSBTs, so any devices your coordinator supports can share a wallet. Mixing vendors means one firmware flaw cannot reach every key.
What happens if I lose one key in a 2-of-3 multisig?
You can still spend with the other two. Create a new 2-of-3 with a replacement device and move your bitcoin into it, so you are back to having a spare key.
Do multisig transactions cost more in fees?
Yes. A multisig spend carries two signatures and the script with all three public keys, so it is larger than a single-signature spend, and Bitcoin fees are charged by size. For long-term savings that rarely move, the difference is small.