On a shared wallet, if one of the recipients deleted their wallets off their phone, is there a way to rejoin? We only had one 12 word backup for the main holder on their phone. The second person, on their phone didn’t get one(me). That I know of, I guess. But I deleted the wallet by accident. Now, is there a way to get back in there as I am the second co-signer and kind of need to have access to the wallet. The first person is trying to send me wallet invites, etc, but I really don’t get it. It’s not working nor do I have the knowledge of this app. I just know for sure he had set it up so both of us needed to agree to use it or spend it. Now, I don’t even have access to the wallet and we can’t figure out how to get that back. Are we out of luck?
Any money sent to a 2-of-2 multisignature address will be forever inacessible if one of the private keys is deleted (e.g. by uninstalling the phone app that holds them) and no backup was made and no recovery phrase was recorded.

There's a common aphorism that circulates in the bitcoin world in various forms, sometimes described as Bitcoin Rule 0


No private keys -- no Bitcoin
Not your private keys -- not your Bitcoin


The latter refers to web-wallets where the wallet-provider business holds the private-keys and their customers do not, or where an online "friend" creates a watch-only wallet for you. The first form of the aphorism is apt here.


One fifth of Bitcoin is permanently lost