To take advantage of these prices you will need to prove you are not a business traveller, on the way to the airport, so you will need to give either your flight details or your holiday booking reference. I don't think you will need to provide this when you arrive at wakefield-westgate station but you may be asked to give them on yr journey from the station to belfast-international airport.
Going to the airport on the train is great, you can take a nap, read (even at night), play travel scrabble, or just gaze out of the window... The other caveat to buying these cheap train tickets from wakefield-westgate station to belfast-international airport is that there must be at least two grown ups travelling together. But another great advantage is that children go free. All children under 5 go free, and then one child over five but under 16 per adult travelling on the train to belfast-international airport.
make sure you leave enough time to get to the airport early enough to eat, shop and so on, so check the times of trains from wakefield-westgate station before you go. If you end up with time to kill at the airport you can always read a book or play a game again! As you have bought your ticket in advance, you don't need to worry about the opening hours of the station.
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