There are good train links from the airports although it is important to note that prices vary and the Oyster card is not valid on these overground routes.
Confusingly, there are two trains serving Heathrow and they both run to Paddington Station. The first is the direct Heathrow Express service. It costs £16.50 one-way (£32 return) takes around 15 minutes and departs from all 5 terminals.
The Heathrow Connect is cheaper, costing £7.40 one-way and £14.80 return. Travel time is about 40 minutes as the train makes about 5 stops en route to Paddington and departs from terminals 1,2,3 and 4 only. A free shuttle bus connects passengers to terminal 5.
Both services start running at around 5.00am with the last trains departing around 11.00pm. The Heathrow Connect train leaves every half an hour Monday to Saturday (every hour on Sundays) and the Heathrow Express departs every 15 minutes. Online booking is possible for most routes.
Stansted Express trains from Stansted Airport arrive into London Liverpool Street in east London and also stop at Tottenham Hale near the northern end of the Victoria line. Tickets are £18 one way, £26.80 return and journey time is 50 minutes. Trains depart every 15 minutes, starting at 3.40am from Liverpool Street and 5.30am from Stansted. The last train departs at 11.45pm although there are some later services with minor restrictions. At Liverpool Street connections can be made with the Central, Circle, Metropolitan and Hammersmith and City tube lines.
First Capital Connect trains leave from Luton Airport Parkway station to St. Pancras and London Bridge stations. Tickets start at £9.90 for a single and £20 for an open return. Journey time is 1 hour to St. Pancras and there are usually four or more trains between 5.30am and midnight although there are also a few sporadic departures during the small hours.
The station at Luton is not at the airport but a short hop on a shuttle bus connects passengers and this should be free with a valid train ticket. The Luton-London train makes some other stops in London but it’s advisable to check the timetables for these destinations.
Alighting at St. Pancras will provides connections to six different tube lines and the Eurostar trains. Further south, London Bridge is also well connected with access to the Northern and Jubilee lines.
The options for Heathrow may seem confusing but there are even more trains to choose from coming from Gatwick Airport. Three different train lines serve Gatwick Airport, with the main terminals being Victoria and London Bridge stations.
The Gatwick Express is a 30-minute train ride to Victoria station. Trains depart every 15 minutes between 5.00am and 11.45pm (with a couple of trains leaving between 3.30am and 5.00am) and cost is £16.90 single or £28.80 return.
For a cheaper ticket, look to Southern Railway and First Capital Connect. Southern Railway trains, which depart to London Bridge take 50 minutes and singles start at £7.90. First Capital Connect trains to Victoria take 30-50 minutes and singles start at around £10.90. Both Southern and First Capital have advance tickets available for purchase online for only £5 one way so it pays to buy before the day of travel.
Finally, traveling by national rail into London may qualify for special rail-related discounts available to many London attractions.
