When you add your hardware device(s) to Casa to create your multisig keyset, you're creating an entirely new set of public and private key pairs that are ready to receive and secure your Bitcoin.
Hardware devices like Ledger, Trezor, or Coldcard are commonly used as single-signature wallets, with a single set of keys, and single backup.
When the hardware device is added to a Casa multisig setup, its function with Casa is being one of several signing keys in your multisig keyset, rather than its own wallet.
"I added the hardware device to Casa, but I don't see my bitcoin in Casa"
If you have funds on the hardware device's single-signature wallet, it's expected that you would not be able to see those funds in Casa. Your BTC does not automatically become secured by multisig just by adding the hardware device(s) to Casa.
In other words, you aren't importing your existing hardware device keys to Casa, but rather using the hardware device as part of a different, initially-empty, newly-created keyset.
In order for your funds to be secured with Casa multisig, you'll need to send your BTC to the deposit address shown in your Casa App's multisig keyset.
- If you're using a Ledger, you would send funds to Casa using the Ledger Live App.
- If you're using a Trezor, you would send funds to Casa using Trezor's web interface at trezor.io.
- If you're using a Coldcard, you would send funds to Casa using an open-source app software like Electrum.
"When I add my hardware device to Casa, will it affect the other funds on it?"
No - setting up your Trezor, Ledger, or Coldcard as a signing key with Casa will not affect the Bitcoin or other coins you may have stored on the device's single-signature key in any way.
As a best security practice, whatever hardware device you add to Casa should be used exclusively for Casa.
"Can my backup seed phrase restore the Casa signing key?"
Yes - if you've retained the seed phrase for your hardware device, then that seed phrase can be used to recreate your Casa signing key on a new hardware device, without making any changes to your keyset.
Choosing to retain the seed phrase is optional, but our security model does allows for a "seedless" setup where you don't retain your seed phrase.
See Seedless Multisig for more information about what's right for you.