"77002" wrote in message
...

So one arrives, utilizing a perfectly valid ticket, at Blackfriars.
But, one cannot exit on the South Bank because it is managed by
another operator.

No, you definitely can arrive by tube and exit on the south bank via the NR
station. The only time you'll pay an avoidable fare is if you walk in off
the street AND cross the bridge AND exit without making a rail or tube
journey. This is exactly what happens if you enter and exit anywhere else,
it is NOT specific to Blackfriars at all. This is what is explained (badly)
by FCC on their website.

However this is exactly what we've already explained in uk.railway, so for
those joining recently from uk.transport.london, there's probably no need to
reply.

Paul S