The home office's checks there were quietly discontinued a short while after they were rolled out - a short while after the Windrush scandal broke. Regardless, identifying bank accounts possessed by illegal immigrants is probably a use case about as legitimate as anything about controlling immigration is.
(I tend to think the home office is terrible and inhumane and that in general immigration policies are terrible and inhumane, but the above is in the context of those)
Regardless, there is no such thing as people "disqualified from banking". The CMA9 banks (who are required to offer basic bank accounts) have fairly limited leeway to decline accounts to someone (though having defrauded that particular bank is one valid reason why)
(I tend to think the home office is terrible and inhumane and that in general immigration policies are terrible and inhumane, but the above is in the context of those)
Regardless, there is no such thing as people "disqualified from banking". The CMA9 banks (who are required to offer basic bank accounts) have fairly limited leeway to decline accounts to someone (though having defrauded that particular bank is one valid reason why)