Stir uses Plaid, the leading global software for secure connections between bank accounts and other tools. Stir might lose connection to bank accounts through Plaid, but this is not a security concern. Certain events may trigger a break in connection, like updating your bank credentials or changes in your bank's security settings.
To reconnect a bank account, go to 'Settings' and scroll down to the 'Bank Accounts' section, then click 'Reconnect Account' to the right of the disconnected bank account.
