Transferring from Heathrow Terminal 2 to Terminal 4 is a relatively simple process that utilizes the airport's free inter-terminal transport system. The most efficient way is to follow the signs for "Underground" or "Trains" and take the Elizabeth Line or the Heathrow Express. These trains run frequently between the "Heathrow Central" station (which serves Terminals 2 and 3) and Terminal 4; the journey takes about 15 to 20 minutes. Crucially, this transfer is free if you use a contactless payment card or an Oyster card—the system will recognize the "inter-terminal" journey and charge £0. Alternatively, you can take the Piccadilly Line (subway), but you may need to change at Hatton Cross depending on the direction of travel. Taxis and "Hotel Hoppa" buses are also available but can cost between £15 and £25. In 2026, passengers are advised to allow at least 30 to 45 minutes for the total transfer, especially if they need to clear security again at Terminal 4 before an international departure.