"David Cantrell" wrote in message
k...

I normally have a Z1-4 travelcard, but if I get a ticket from BZ4 to
wherever, the train doesn't have to stop in zone 4 for the ticket to be
valid.

BZ tickets are the big exception to the normal rule that if you are
combining multiple tickets for a single journey, you need to travel on
trains that stop at appropriate places.

As is regularly pointed out, if you did need to stop at a 'boundary station'
there'd be even less point in having the tickets. This is precisely why
they are issued from the boundary between two zones - which as a glance at
the map shows is not always at a station.

Paul S