From the Wikipedia page [1]
Earlswood railway station serves Earlswood, south of Redhill, in Surrey, England. It is on the Brighton Main Line, 21 miles 50 chains (34.8 km) down the line from London Bridge via Redhill and south of the junction between the Redhill line and the Quarry line. Train services are provided by Southern.
Although the station is outside Greater London, Oyster cards can be used.