So Chiltern is now accepting contactless out as far as Wycombe. This is great news. So, I get on at Wycombe and head into London for the day, paying by Contactless. I use the same contactless card on LUL services and for the return journey back to Wycombe. Does Chiltern talk to LUL re fares so I would only be charged the same as a Travel card from Wycombe or will Chiltern charge me for a return to Marylebone then LUL charge me up to the fare cap for all the tube journeys? Would the latter be more expensive than a travel card (I suspect it would be)?