Advance tickets under £10 sound tempting, but read the small print
Trainline Advance Fares on the Gatwick–London routes trade flexibility for price: if you commit to a specific train, one-way tickets can drop under £10 when bought early. Journey time into central London sits around 30–45 minutes, depending on operator and whether you pick Southern, Thameslink, or another service. This is an online ticketing play, not a special train; it’s just a different way to pay for the same departures leaving Gatwick every 10–15 minutes.
You buy Trainline Advance Fares in the app or on the website, then use a mobile barcode at the Gatwick barriers in the North and South Terminal station area. Mobile tickets from Trainline usually scan fine at the gates, but regulars flag patchy signal on the platforms, so download the ticket to your phone wallet before you lose 4G. The Advance ticket locks you to a specific departure time listed right on the ticket, unlike flexible Off-Peak or Anytime options from the same Gatwick Airport station.
Price is the hook: on quieter trains, Advance fares Gatwick–London can be half the cost of a walk-up Off-Peak, dropping to that sub-£10 range. The catch is Trainline’s booking fee, which often shows as a small extra line item compared with buying direct from Southern, Thameslink, or GWR apps. Reddit regulars complain that the fee adds up on multiple tickets, especially if you’re buying for a family of 3–4.
Risk sits with delays. If your inbound flight lands late into South Terminal and you miss your specific Advance train, you’re usually buying a fresh ticket at the station for the next service that leaves 10–15 minutes later. Reddit threads are full of people stuck with non-refundable Advance fares after disruptions, which is why many frequent flyers pay extra for flexible tickets on the inbound leg only. Some then use Advances on the return from London to Gatwick, where a set departure time from Victoria or London Bridge is easier to hit.
What regulars do: they often use Trainline for comparison, then jump to the operator’s app to buy the same Advance at the same time, but without the Trainline fee. Others skip Advances entirely for airport runs and stick to Off-Peak or Anytime, especially when landing after 18:00 when delays are common. If you still want the deal, book the Advance for a train at least 60–90 minutes after scheduled landing to give yourself some buffer for immigration and bags.
Final tip: screenshot your QR codes and have them open before you head down to the Gatwick Airport platforms, so a dead signal or slow app doesn’t make you miss the exact train your Advance ticket is tied to.