In message
, MIG
writes

On 5 Feb, 17:22, Mizter T wrote:

Putney (z2/3) to Richmond (z4) - pax holds a z1&2 Travelcard for their
commute into town (train to Waterloo then W&C line into the City), but
they want to go and have a walk and drink by the river.

Ang on; aren't those just examples where they'd be on PAYG for the
whole journey?

That's exactly what a lot of people would assume, because that is how
things work when using a travelcard + PAYG on TfL. In fact, your comment
goes to the very heart of the confusion about OEPs.

Unlike TfL, almost all of whose stations are gated, the TOCs weren't
willing to take the revenue risk of people who travel beyond their zones
simply not touching out at one of their many ungated stations, and thus
not paying anything for travelling out of zone.

Hence, an OEP is required. Touching in at Waterloo (in this example)
deducts a maximum cash fare, despite the fact there is a Z1/Z2
travelcard on the Oyster. The actual PAYG fare is then adjusted when
touching out (at Ricmond in Zone 4) - basically resulting in a charge
from the boundary of Zone 2 to Zone 4.

The theory is that if you are gripped on NR while travelling out of zone
without an OEP, you will be charged a penalty fare. The OEP acts as
evidence that money has already been deducted for travelling out of zone
when you touched in at Waterloo (*).

As has been said, there is considerable doubt that an appeal would find
such a penalty charge fair or even legal, given that a maximum cash fare
has already been paid at the start of the journey. It has been said (I
think by Caroline Pidgeon at Mayor's Questions) that some TOCs are
deliberately not issuing penalty fares in these circumstances in order
to avoid the courts declaring the entire OEP system invalid.

(* If you change your mind and get out at Putney, in Zone 2, the cash
fare is reimbursed when you touch out, and the OEP stays on the Oyster
for when you next want to travel out of zone).
--
Paul Terry