To take benefit of the best prices you will need to prove you are a leisure traveller, on the way to newcastle airport, so you will need to provide either your flight details 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 give them on your travels from saltburn station to the airport.
Going to the airport on the train is great, you can sleep, read (even at night), play a game, or just stare out of the window... The other restriction to buying these cheap tickets from the station to the airport is that there must be at least two grown ups travelling together. But another great advantage is that kids go free. All children under 5 go free, and then one child over five but under sixteen per grown up travelling on the train to newcastle 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 newcastle airport you can always read a book or play a game again! As you have bought your train ticket in advance, you don't need to worry about the opening hours of saltburn station.
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