As from 14 December contactless payment for train tickets has been extended to Stansted and Southend Airports, so will now apply to all 6 London airports which are open to scheduled flights.
As always, if you have a railcard, verify (on the TfL fare finder tool) whether railcard tickets or contactless is the cheaper option. Also if you intend to use the 2-4-1 offers for various attractions in London actual tickets may still be advantageous.
This is part of another tranche of extensions- to another 49 National Rail stations-
Ashtead
Aylesbury
Aylesbury Vale Parkway
Baldock
Beaulieu Park ((the brand new station near Chelmsford, opened a few weeks ago)
Billericay
Bishop’s Stortford
Box Hill & Westhumble
Chelmsford
Dorking (Main)
Dormans
East Grinstead
Great Missenden
Harlington
Harlow Mill
Harlow Town
Hatfield Peverel
Hitchin
Hockley
Hurst Green
Ingatestone
Knebworth
Leagrave
Leatherhead
Letchworth Garden City
Lingfield
Little Kimble
Luton
Monks Risborough
Oxted
Princes Risborough
Prittlewell
Rayleigh
Reigate
Rochford
Roydon
Saunderton
Sawbridgeworth
Southend Airport
Southend Victoria
Stansted Airport
Stansted Mountfitchet
Stevenage
Stoke Mandeville
Watton-at-Stone
Welwyn North
Wendover
Wickford
Witham
Woldingham