To take advantage of these prices you will need to prove you are a leisure traveller, on the way to the airport, so you will need to provide either your flight numbers or yr 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 provide them on your travels from brent-cross station to the airport.
Going to stansted airport on the train is great, you can sleep, read a book (even at night), play a game, or just stare out of the window... The other restriction to buying these cheap train tickets from brent-cross station to the airport is that there must be at least two grown ups 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 the airport.
make sure you leave plenty of 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 end up with time to kill at stansted airport you can always read or play a game again! As you have bought your train ticket in advance, you don't need to worry about the opening times of brent-cross station.
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