I use the phone system that Dave pointed me to – an earlier version of the BT8600. It is basically the mobile Truecaller for landlines. I block everyone who is not on my white-list, they can then state their name/business and I can then allow or blacklist if I want. It filters out foreign scammers as they do not want to spend the time waiting for my approval.
Brilliant piece of kit – well worth the money.
[edit] I have forgotten all the possible setup options. Iirc I have auto-dropped all foreign callers except those on my white list. I guess those using an internet chat via a uk number could get in but they do not bother. Even the UK PPI irritants do not bother!
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