To take advantage of these prices you will need to prove you are not a business traveller, en route to gatwick airport, so you will need to give either yr flight numbers or yr holiday booking reference. I don't think you will need to provide this when you arrive at edgware station but you may be asked to provide them on your journey from edgware station to the airport.
Going to the airport by train is great, you can take a nap, read a book (even at night), play travel scrabble, or just gaze out of the window... The other caveat to buying these cheap tickets from the station to the airport is that there must be at least two adults travelling together. But another great benefit is that kids go free. All kids under five go free, and then one kidover five but under sixteen per adult travelling by train to the airport.
be sure to leave enough time to get to the airport early enough to eat, shop and so on, so check the times of trains from the station before you go. If you have time to kill at gatwick airport you can always read a book or play travel scrabble again! As you have bought your train ticket in advance, you don't need to fret about the opening times of the station.
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