Trains offer the fastest service between Heathrow and central London. There are three major services available to passengers:

Heathrow Express
These trains depart four times per hour and take only 15 minutes to reach London Paddington. Travel time is a bit longer to and from Terminals 4 and 5.

The Heathrow Express allows you to travel in comfort on modern trains with plenty of space for baggage, air conditioning and free TV. You are also able to use your mobile phone while the train is the tunnel.  If you are looking for a spot to get some work done or just relax there is a quite zone carriage located on every train. Or if that does not take your fancy you have the option of upgrading to First class and avail of all the services it comes with. First class has extra leg room, larger more comfortable seats complimentary magazines and news papers with the current news and finally better tables to work from.

Trains are scheduled to run between 05:10 and 23:25 from Paddington, and between 05:03 and 23:58 from Heathrow.

You are able to purchases tickets online, on the train or at the station. The standard-class single fare is £26 on board or £21 in advance. Returns are £39 on board or £34 in advance.

Heathrow Connect
While Heathrow Express offers direct service to London, this train makes a few stops along the way. With that in mind, it takes just over 25 minutes to reach London Paddington. Of course, this means it’s the more affordable option.

London Underground
The Tube offers the most cost-effective transport to the airport. The Piccadilly line has three airport stops – one for Terminals 1, 2 and 3 connected by underground walkway) and another each for Terminals 4 and 5 (connecting directly to the basement of the terminals).