On 3 Jan, 15:52, trainmanUK wrote:
The whole reason for these OEP is that many NR stations do
not have barriers so if you get to your destination and see no one
there you can just walk off the station with out paying (Touching out)

Not so....all in-zone NR stations are or will have Oyster validators -
and it is your responsibility toi touch out. Barriers or no.

How on earth does Oyster know how much to deduct from your PAYG if it
doesn't know in which zone you travelled to?
It deducts £1.50 as you touch in (with an OEP loaded), but it may well
need to deduct additional funds (if you have a Z12 Travelcard and go
to zone 6, for example) - but unless you touch out, Oyster won't know
how much to take in total.