It’s nice and easy: one account, two members. Shared accounts allow you and your partner to share access to your Casa account and your keyset. Both you and your partner receive the same onboarding and receive full Casa support, including the Casa Recovery Key. Think of it as a joint account for your bitcoin. This arrangement allows you to create a simple legacy plan for your bitcoin.
If you pass away, your partner retains immediate access to your bitcoin, and upon presentation of a death certificate, the account transitions to a personal account.