Being so close to Britain's largest airport and many attractions such as Thorpe Park, classing these stations outside the Zones has made fares expensive and fines frequent. As the population of London grows, so must the Zone areas. Please include these stations, within the M25, in Zone 6. Policing and fining of unsuspected passengers/tourists would also decrease.
There are many stations not in 'London' which are included in the Zones so there is no reason why our stations aren't included.