On 19 Nov, 14:14, wrote:
But is there any way of doing this without having to get off the train
at Tottenham Hale and touch out on the Oyster? Otherwise I'll have an
unresolved journey, won't I?

Can't be done - you can't combine Oyster PAYG with other ticket types
without breaking your journey, essentially.

(If you're feeling cheeky before you board the train you can touch an
intermediate validator in a behind-barrier interchange. Then you're
touched in if a ticket inspector checks but don't get an unresolved
journey when you leave the system. There isn't a way to do this at
Liverpool Street, however)

U