Help with travel planning in London

[Pubsignman]

Thanks for the quick reply Pubsignman,

Another quick question is the Oyster card valid on Souteastern trains from Stratford to St Pancrass.

Thanks Alan

I don't think you can use it on that route. Generally you can use a Pay As You Go Oyster card on any train journey within zones 1-9, but there are a few exceptions to this and the high speed Southeastern service between Stratford International and St Pancras International is one such exception.