Recover a vault in Electrum
Rebuild your vault in Electrum from your own seed words and spend from it without SignBit. Do this once as a drill, so you know it works before you ever need it.
1. What you need
- Enough of your own keys to meet the vault's threshold, as their seed words. On a 2-of-3 vault that is two keys, for example yours and your recovery key.
- SignBit's key in the format Electrum asks for. On your vault page, open the SignBit key card and choose Show Zpub. Copy it and keep it with your backup now, while you can reach us.
- The number of keys in the vault and how many must sign, for example 2 of 3.
- Electrum, downloaded from electrum.org, with its signature checked.
If all you have is the backup file from your vault page, use Sparrow instead, since it reads that file directly. See Recover a vault in Sparrow.
2. Start a multi-signature wallet
Open Electrum and choose File → New/Restore. Give the wallet a name, then choose Multi-signature wallet.
Set the two sliders to match your vault, one for the number of cosigners and one for how many signatures are required.
3. Add your first key
Choose I already have a seed and type the seed words of one of your keys. Before you continue, open Options and choose BIP39 seed, because the keys SignBit works with use the BIP39 standard rather than Electrum's own.
When Electrum asks for the script type, choose native segwit multisig (p2wsh) and leave the suggested path, m/48'/0'/0'/2', unchanged. Electrum may write it as m/48h/0h/0h/2h, which is the same path, since h and ' mean the same thing.
4. Add your second key
On Add Cosigner 2, choose Enter cosigner seed and repeat the same steps with your second key, entering its seed words, choosing BIP39 seed under Options, then native segwit multisig and the same path.
On every cosigner screen, Electrum shows "your master public key" in a box. That is always your FIRST key, whichever cosigner you are adding. It is not the key you are being asked for, so there is nothing to change.
5. Add SignBit's key
On the last cosigner screen, choose Enter cosigner key and paste the Zpub you saved from your vault page. Electrum only needs SignBit's public key. It lets Electrum work out the vault's addresses, and it cannot sign anything.
Finish the wizard. Electrum asks for a password to protect the wallet file on this computer; choose a strong one.
6. Check the balance
Electrum finds the vault's transactions on its own. The balance should match what SignBit shows for this vault, to the satoshi.
For a second check, open Receive and compare the first address with the first receive address on your vault page. If they match, Electrum has rebuilt exactly the same vault.
If the balance is zero or the addresses differ, stop and do not send anything to this wallet. The usual causes are the wrong seed type (Electrum instead of BIP39), the wrong script type, or sliders that do not match the vault.
7. Spend without SignBit
Because this wallet holds enough of your keys to meet the threshold, Electrum can sign on its own. Open Send, paste the destination into Pay to, enter the amount, and choose Pay….
Electrum shows the amount and the fee. Move the slider for a faster or cheaper fee, or choose Preview to see every input and output first. Choose OK, enter the wallet password, and Electrum signs with both of your keys and broadcasts in one step.
The payment appears as Unconfirmed until the next block, then confirms.
The Bitcoin network does not know or care that SignBit exists. Once the transaction confirms, it also appears in your vault's history on SignBit, because it is the same vault.