A word of warning to future travelers. We took a group of 16 persons to London landing at LGW. Bought 1st class tix for the Gatwick Express just because we thought 1st class would give us carriages with fewer people because most everyone else will be in 2nd class, right? Wrong. Not only could we not sit in 1st class, but we couldn't sit in 2nd class either. Heck, we couldn't sit at all, and a few of us were stuck standing in the loud unairconditioned breezeway between carriages along with 5 or 6 other travelers. Some poor soul attempted to use the WC and we had to move all of the stacked luggage and bodies to get to the door only to find it LOCKED with no one inside. It was just plain old locked. So if you're thinking of riding the Gatwick Express just be forwarned to not waste money on 1st class tickets. BTW - our tickets were never even checked.
Thanks for your report Tim... its the first time I have heard of the Gatwick Express being overcrowded. I use it as transport to Gatwick and then continue south sometimes but have never seen it like that. Was something else going on like cancelled trains? You worry me saying you were standing between carriages. That is a very very unsafe place to be, just a bit safer than riding on the bumper. If you want more detail about why they are so unsafe, ask. I deal with them every day. There are usually Gatwick Express trains every 15 minutes. Were lots of people left on the platform? BTW - how was the return trip? Can I speak for the ticket check? If the train was so very overcrowded would you really have expected a conductor to try to fight their way through the train, especially if they couldn't get between cars? I'm sorry you had a bad experience. I hope it didn't spoil the holiday for you and your group.
Between 7 and 9 am, and 5:30 to 6:45pm the Gatwick Express starts from or continues to Brighton. This means the trains will be used by commuters, and there are plenty along that route that will choose 1st class. It maybe though that it was a short train (5 instead of 10 coaches).
I thought they checked Gatwick Express tickets at turnstiles. If you spend enough time on the Gatwick Express website you can find cryptic footnotes about the Brighton service which negate their first class offers of "Large, comfortable, reclining seats, Tables which you can work from, Complimentary copy of The Telegraph, At seat refreshment service, Complimentary tea, coffee, and water**" http://www.gatwickexpress.com/en/tickets-and-fares/ticket-types/first-class/ The regular rail service offered by Southern from Gatwick to London Victoria is cheaper than the Gatwick Express and takes only a little longer. Depending on your London destination, rail service from Gatwick to London Bridge, Blackfriars, City Thameslink, Farringdon, or St. Pancras may be more appropriate. Fares can be less tan £10.