In message , Tristan
Miller writes

Is it permitted to travel between Liverpool Street and Maryland with a Zone
1–3 Oyster travelcard? There's no Oyster card reader to touch in or out at
Maryland, though I've made the journey both ways several times without
apparent incident. That is, going from Maryland to Liverpool Street, the
exit gates have always opened upon swiping my card, and going either way,
I've never had any money deducted from my PAYG balance.

You can use an Oyster Travelcard on that route, but not PAYG (not until
2nd January, that is).

--
Paul Terry