A bit longer -
Initially Royal Mail & (General) Post Office where the same company, Post Office to send mail and a Royal Mail office to collect misdelivered post and parcels.
In the early 1970s they separated but maintained the close relationship, during the 1980’s and 1990’s both where privatised and had to look at other ways to maintain revenue streams, the Post Office does so many things other than mail, telephone, broadband, banking, insurance, passport services, etc. Only recently the Post Office has now started offering alternative postal services and couriers to Royal Mail.
I will post pictures of my local post offices in the other thread about ''What Your Post Office Looks Like"
Isle of Man (IOM) I have included as I have been there a few times and visited Post Offices there (and on their mailing system from stamp orders)
IOM is an overseas territory of the UK located within the British Isles and their mail system was part of the RM, but in 1973 became a separate entity and is managed by the Manx government.
All mail on the Island is routed through RM in Great Britain & Northern Ireland.
Other overseas territories such as the Channel Islands & Gibraltar have their own logos too
Looking for the logo I just realized that they have changed it last year (now is the one on the right), but I guess that because of the pandemic all the post offices still use the one on the left, and of course is a messenger pigeon in both cases!
Sometimes they use the crown and post horn logo, either alone or with the PostNord logo. I think they use this one often to mark the shops that offer post services (no post offices anymore, just counters at shops), but honestly I have apparently paid so little of attention I can’t even recall that… So I will have to check next time I do groceries.