"Roland Perry" wrote:

Peter Masson remarked:
The passenger may have started at a station where the ticket office was
not
open. If he had purchased a PTT he will not be liable for a penalty fare,
but will have to exchange the PTT for the appropriate ticket. Trains which
serve City Thameslink are DOO, so it is not normally possible to exchange
a
PTT for a ticket on the train.

Yes, that's a possibility, but for a tiny minority of passengers. I expect
the rest will be asked to pay a penalty fare.

Really? The excess fare window at my local station (Barking) does a brisk
trade in ticket sales, and it is evident that few questions are asked,
despite both c2c and London Underground operating a Penalty Fare scheme in
this area.

Chris