To take advantage of these prices you will need to prove you are a leisure traveller, on the way to heathrow airport, so you will need to provide either your flight numbers or yr holiday booking reference. I don't think you will need to give this when you arrive at lincoln-central station but you may be asked to give them on your journey from lincoln-central station to heathrow 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 lincoln-central station to heathrow airport is that there must be at least two grown ups travelling together. But another great benefit is that children go free. All kids under five go free, and then one kidover 5 but under sixteen per adult travelling by train to the 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 the station before you go. If you end up with spare time at the airport you can always read a book or play travel scrabble again! As you have bought your ticket in advance, you don't need to fret about the opening hours of the station.
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