wrote:
If you have a Travelcard season, unresolved journeys don't matter (as
long as the endpoint is within your zones). And PAYG isn't valid on
National Rail between Ealing Broadway and Paddington.

How would it "know" that the endpoint was in my valid travelcard zones
(1-3 incidentally - I have some PAYG credit as well)?

I could just as easily gone to a tube destination in zone 5 and failed
to touch out; isn't catching that possibility the point of the £4
charge?


That would be no different to travelling beyond the validity of a paper
travelcard. If you were caught there, you wouldn't have a valid
ticket.

A travelcard on Oyster just gets you through the gate. There's no
other reason to touch it in or out.