In the US Caller ID has been so hopelessly compromised (for almost two decades now, that's on Congress) that financial institutions almost never make outbound calls, and only ever use standardized published numbers; I wasn't aware other countries differ so much.

Please tell us more context with regard to your UK banks making multiple unannounced calls demanding your ID ... were you an individual customer? finance director? MD? or what? Why on earth do they do that? Have you told them in writing not to? There must be more backstory to that.