The link https://www.bt.com/landline/calling-costs/ regarding set up fee seems to to relate to Internation Calls.
Yes. See message 8
I read message 8 before posting and came to the conclusion my posting was looking at something different to that being quoted in message 8.
The link we both posted has a link to the PDF tariff guide, which I hadn't read when I posted message 6, but had when I posted message 8 after I had realised the set up fee quoted was for International Calls only. 😀