Hi Guys,

Was travelling with a 7 day Z12 Oyster travelcard today.

I had just entered Leicester Sq tube this evening when, because of
announced delays, I decided I'd change my mind and walk up to
Tottenham Court Road station and catch the Central line instead.

However, when I tried to leave Leicester Sq station,
the barrier refused my Oystercard (I didn't notice the code), and
when I approached the barrier supervisor he just waved me out through
his gate, leaving my card with no exit record.

This left me worrying all the way up Charing X Road, that my
Oystercard was now going to be all out of sync somehow, and that I
might not be allowed back into the system at TCR.

Luckily the barriers let me in as normal at TCR, but this left me with
a couple of questions, which I wondered if any of you wouldn't mind
answering?

Q1)
When travelling with an Oyster Travelcard, how does the system handle
a situation where you somehow exit a journey without exit-validating
your card?
Is there a danger that you could be charged a full 6 zone single
ticket from your pre-pay balance like would happen on a pure pre-pay
journey, or does the system assume you made a legal journey if your
next entry is 'within your zone'?

Q2)
In the above scenario where you exit from your entry station without
travelling, what would have happened if I had been travelling on an
Oyster PRE-PAY ticket?
a) Would I have been let back out of the barrier at Leicester Square
and charged a zone1 single?
b) or, not let back out of the barrier at Leicester Square, and
therefore charged a full 6 zone single if the assistant waved me
through?
c) or could I have got back out of Leicester Square with no charge?

If I would have been charged on pre-pay , is there an official
mechanism to avoid this? In the past, when travelling with a single
ticket, I've changed stations like above, by simply explaining to the
ticket gate guys what Id like to do, and they've let me in/out.

Many thanks for your replies!