Until 2012, free transfer was not possible between terminals via the Underground, in contrast to the Heathrow Express. In January 2012, free travel was introduced for Oyster card holders between the Heathrow stations on the Piccadilly line. Journeys from Heathrow Terminal 5 to Terminal 4 via the Piccadilly line require a change at Hatton Cross; this journey is free, despite Hatton Cross not being part of the free travel zone.
The station is staffed by Heathrow Express staff unlike the underground stations at Heathrow Terminal 4 and Heathrow Terminals 1, 2, 3. The London Underground section of the station is situated in Travelcard Zone 6. It is the westernmost below-ground station on the London Underground network. Although situated underground, parts of the station's roofing are made of translucent ETFE laminate panels, allowing natural daylight to flood down both ends of all six platforms. In addition to the above rail links, the T5 Rail Station also has two safeguarded "heavy rail" platforms for use by a west-facing connection to the National Rail network. This proposed link starting from near the existing Staines railway station is called Heathrow Airtrack and would offer half-hourly services to London Waterloo, Reading, Woking and Guildford. BAA have published as part of the Airtrack consultation that they also want to extend the Heathrow Express to a new platform at Staines railway station. The plans originally included the rebuilding of Staines High Street railway station but, due to local opposition and passenger projections, the station has been dropped. The station has lifts and escalators.
Connections: Heathrow Express. Heathrow Connect. London Buses Routes 350, 423, 482, 490 and Night Route N9 serve the station.