There's obviously some magic to glue different accounts together without user input, so I can see my Scottish Widows pension and Halifax credit card balances in my Lloyds Bank app[1], even though I have separate logins for each brand's website and app. Possibly my National Insurance number and address I'd guess? But I can see it going badly wrong if they get the magic merging wrong...
[1] Clearly I need to open a Bank of Scotland account to get the full set.
But I suppose you mean connecting these directly based on the national insurance number, rather than relying on user consent to use OpenBanking to see them all together in one place.
My daughter opened an account using the app only (Scan passport, video clip to authenticate) got the card the next day and setup up savings, investing ISA's with a few clicks. Again incumbents not willing to innovate until someone disrupts, but probably too late.
https://www.ft.com/content/a304cf5a-5d91-4d4d-a41f-16651b59e...
