I'm curious as to whether the OP has made a mistake in saying that the
system charges him £3 rather than £3.50 - if it is £3.50 then this
would fit my hypothesis that the system either can't cope or hasn't
been configured to cope with journeys that are subject to two separate
Oyster PAYG fares brackets - i.e. 'standard' PAYG fares (weekdays
7am-7pm), and 'discount' PAYG fares (all other times, plus most of the
day on the Watford Jn - Euston line) - and simply defaults to charging
the more expensive fare.

Alternatively if the OP really is being charged £3 then perhaps
something even odder is going on, with the system charging the Euston
to Watford Jn fare (£3 'discount', £5.50 'standard').

I would certainly suggest that the OP contacts the Oyster helpline for
a refund - perhaps someone might look into this and change how things
are configured.



It is definitely £3 each way. I wonder if this is the peak time fare
from the Zone 3 boundary to Watford Junction? (certainly it is £3 from
Wembley Central to Watford Jn according to the single fare finder).
Looks like for some reason the special discount travelling away from
Euston isn't on extension fares which is a little odd. Have contacted
TfL but not too hopeful . . .

I'd suggest getting a second PAYG card, touching out on your travel
card and then in on your PAYG card at willesden.

At the moment holders of Travelcards on Oyster don't actually need to
touch-out, so if there are still any standalone Oyster readers at
Willesden Jn then the OP could simply touch-in his second Oyster card
on one of them and that should work fine. Just don't get them muddled
up (different colour wallets is the obvious suggestion!).


Good idea, but would need to walk out the gates and back in again as
no Oyster readers on or between the platforms . . . All seems a bit
daft!