The Government Says

Simpler train travel to London airports as tap-in, tap-out expanded across south-east England

Simpler train travel to London airports as tap-in, tap-out expanded across south-east England
Local copy of contactless-ticketing-station-map.pdf

https://www.gov.uk/government/news/simpler-train-travel-to-london-airports-as-tap-in-tap-out-expanded-across-south-east-england

seen at 02:53, 17 November in News and communications.