To take advantage of the best prices you will need to prove you are a leisure traveller, on the way to the airport, so you will need to give either yr flight numbers or your holiday booking reference. I don't think you will need to provide this when you arrive at the station but you may be asked to give them on your travels from wood-green 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 restriction to buying these cheap train tickets from wood-green station to luton airport is that there must be at least two adults travelling together. But another great benefit is that children go free. All children under 5 go free, and then one kidover five but under sixteen per adult travelling on the train to luton airport.
make sure you leave plenty of time to get to the airport early enough to eat, shop etc, so check the times of trains from the station before you go. If you end up with time to kill at luton airport you can always read a book or play travel scrabble again! As you have bought yr ticket in advance, you don't need to fret about the opening hours of wood-green station.
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