Hooray, you're going on holiday! Boo, you now have to get to the airport. There are so many different ways to get to and from London's airports that it can get a bit confusing — and expensive. Here, we've listed the cheapest and fastest ways to get from central London to Heathrow, Gatwick, Stansted, Luton and City airports.
For all these public transport options, it's worth bearing in mind that the most convenient option is generally a cab (black, minicab, Uber) — particularly if your flight is at a ridiculous hour. It's all very well the trains running all night, but not great if you have to use a night bus to get to the station. If there's a group of you travelling, or you're a family, it could very well also work out cheaper.
Heathrow
Cheap: If you've got an Oyster card and use Pay As You Go, the tube is the cheapest option: £5.10 single adult fare during peak hours, or £3.10 off peak. If you're paying cash, however, the tube is £6 — exactly the same as a National Express coach from Victoria. Depending on the traffic, the journey time is about the same as well: 50 minutes on the tube from (to pick a central example) Leicester Square to Heathrow and 45-55 minutes on the coach — and less lugging your suitcase up and down steps with the latter, too.
Fast: The Heathrow Express from Paddington takes 15 minutes to get to Terminals 2 and 3, with an extra few minutes on top if you want to go to Terminals 4 or 5. It's a journey time that rivals the DLR trip from Bank to City Airport as the fastest possible way of getting from central London to an airport, but comes at a price. A single adult ticket costs from £22, making this the winner in the 'HOW bloody much?' public transport stakes.
If you have a bit more time and a bit less cash, Heathrow Connect takes between 31 and 49 minutes to travel between Paddington and Heathrow, mainly because it makes some extra stops along the way. An adult ticket costs £10.20 from Paddington and less if you want to travel from, say, Ealing. It only goes to Terminals 2 and 3, but there's a regular shuttle service to Terminal 4.
Gatwick
Cheap: easyBuses leave from Waterloo and Victoria, and if you book online far enough in advance you can get a ticket for as little as £2. Even with just a few hours' notice it was possible to get a ticket for £7.95. The journey does take a timetabled 90 minutes, however — and that's without getting stuck in traffic. If you prefer getting the train, an off-peak fare on pay as you go (not Gatwick Express) will cost £8 (although if you're returning, a paper ticket may be cheaper).
Fast: the Gatwick Express from Victoria takes 30 minutes, give or take (it's timetabled as 33, accuracy fans). Adult single fares cost from £15.40 (if you take a Southern service, which isn't technically the Gatwick Express but there you go) to £19.90.
If you're not near Victoria, however, we recommend you investigate the Brighton to Bedford line run by Thameslink. Calling at St Pancras, Farringdon, City Thameslink, London Bridge, Elephant and Castle and a few other stations outside zone 1, it goes direct to Gatwick. The journey from London Bridge takes as little as 37 minutes (changing at East Croydon because of works around the station) and from St Pancras it's 55 minutes with no changes. It's cheaper, too: adult single fares from St Pancras start at £10.30 and from London Bridge it's £9.40. Regular Thameslink commuters will warn you that it's notorious for delays, though.
Stansted
Cheap: the cheapest easyBus to Stansted costs £6 and the journey takes over two hours. Prices can rise to £12 for a journey; a price point we suspect has been deliberately chosen as it appears to be the cheapest possible ticket from central London to Stansted on National Express coaches.
Fast: the Stansted Express from Liverpool Street station takes between 45 and 50 minutes. An adult ticket costs £19. You don't have many options when it comes to Stansted; you very much have to take what you're given.
Luton
Cheap: it's easyBus again, though for Luton you really need to book online significantly in advance: we had to search 11 days ahead before we found a £1.95 ticket. Still, the most expensive journey (£9.95) is cheaper than the equivalent on National Express. The journey is timetabled to take 90 minutes from Victoria, but takes less time (not necessarily reflected in the price) if you can leave from somewhere like Finchley Road or Baker Street tube stations.
Fast: Get the Thameslink train from various stations through the centre of London — it takes 49 minutes from Elephant and Castle, or from St Pancras you could be at Luton Airport Parkway in as little as 20 minutes. Adult fares start from £15.50, but beware you have to catch a shuttle bus from the train station to the actual airport, which takes 10 minutes and is free so long as you've bought a ticket to the airport and not just the train station. (This costs £1.50 more than buying a ticket to the train station, so 'free' in this context is open to interpretation.)
City
Just get the DLR. If you happen to live on the 474 or 473 bus routes you've got it made, but otherwise — get the DLR.