"Peter Smyth" wrote in message
...

Surely for any journey via zone 1 you will have to pass through barriers
where you change from NR to LU (at London Bridge, Balham, Victoria etc).
The only way to get from Streatham Hill to Canary Wharf without passing
any barriers is via the ELL to Canada Water.

So the default fare if there are no intermediate touches, should be the
not-Z1 fare.

That doesn't actually follow for the system in general - don't forget you
could go further 'west' than Balham, maybe changing onto the underground
behind the barriers, at West Brompton for instance (not likely but
possible).

Lack of a zone 1 touch in/out can be overridden by the fact that (as they
point out) some journeys are just defined as being 'via zone 1'. They don't
necessarily have to detect your presence in zone 1, but you sometimes get
the option of telling them you didn't go that way, using an interchange
validator. OTOH for some journeys the interchange validator won't do
anything, because they haven't agreed the detour is likely.

As a further point, the OP mentioned using some sort of travelcard (a
season?) - is he actually using PAYG extensions to that travelcard?

Paul