All four Heathrow terminals are connected by a free internal train network, and Heathrow's own terminal transfer tool lets you look up the exact route between any two terminals. The trains themselves are quick, but you must clear security again at your destination terminal, so build in real time rather than just the train ride. Checked 2026.
This guide covers transferring between terminals when you are not on a single connecting ticket, for example if you are meeting someone, have booked two separate flights, or are visiting a terminal you are not flying from.
How the free inter-terminal transfer works
Heathrow Express, the Elizabeth line and the Piccadilly line Underground all run between the terminals, and all three are free to use for a terminal-to-terminal transfer. You do not pay the normal Heathrow Express or Elizabeth line fare for this; instead, look for the dedicated blue transfer-ticket machines next to the regular ticket machines in each station, or tap in and out with contactless or Oyster if using the Underground, which will not be charged for a terminal-only transfer. Heathrow publishes a terminal transfer tool on its own site where you select your "from" and "to" terminals to get the specific route.
Terminal 2/3 to Terminal 5, and back
Terminals 2 and 3 share one station, Heathrow Central, from which any of the three train services runs directly to Terminal 5 in only a few minutes of actual travel time. This is the most straightforward transfer at the airport.
Terminal 4: the one that needs a change
Terminal 4 sits on its own branch. Getting to or from Terminal 4 usually means a change, either via Heathrow Central (T2/3) using the Heathrow Express or Elizabeth line, or via Hatton Cross on the Piccadilly line. Build in extra time for this transfer compared with the T2/3-to-T5 route, since it involves an additional train and a platform change rather than a single direct hop.
Terminal 2 to Terminal 3: walk instead
Terminals 2 and 3 are close enough to walk between using the underground walkway that also leads to the shared train station, complete with moving walkways (travelators) and space for luggage trolleys. There is no need to use a train for this specific transfer.
Self-connecting on two separate tickets is a different process entirely
If you have booked two separate flights rather than a single connecting itinerary, Heathrow's own guidance is clear that you are not a "connecting passenger" in the airline sense. You will need to pass through immigration, collect your baggage, then go through check-in, bag drop and security again for your next flight, in addition to any terminal transfer. That is a materially longer process than a same-ticket connection, so check your specific airline's minimum connection time guidance and build in a generous buffer rather than relying on the train time alone.
How much time to allow
For a same-ticket connection between terminals (where your baggage is transferred automatically by the airline), most of your time goes on the mandatory security re-screen at the new terminal rather than the train itself, which typically only takes a few minutes between platforms. Many travellers report needing to allow at least 45 to 60 minutes in total for a straightforward T5-to-T2/3 transfer once queueing and security are included, and longer again for any transfer involving Terminal 4, since that route needs an extra change. If your connection window is tight, check with your airline, since most self-connecting or short-window transfers are booked by travellers who assume the train ride is the whole journey and then find the queue at security takes longer than expected.
What if you have mobility difficulties or need assistance?
If you require support during a terminal transfer, Heathrow's assistance team can help, and this should ideally be arranged in advance through your airline, at least 48 hours before travel where possible. See our wheelchair accessible transport guide for more on getting to and from Heathrow itself, and Heathrow's own assistance pages for support once you are airside.
Facilities while you wait
Both the shared Terminal 2/3 area and Terminal 5 have a full range of shops, cafes and seating landside and airside, so a terminal transfer with time to spare is not a hardship. If you are killing time before a longer wait, our guide on is 2 hours enough at Heathrow and leaving Heathrow during a layover cover how to use spare time well.
FAQs
Is it free to transfer between Heathrow terminals?
Yes. Heathrow Express, Elizabeth line and Piccadilly line journeys used purely to move between terminals are free; use the dedicated transfer ticket machines or simply tap in and out on the Underground.
How long does it take to get between Heathrow terminals?
The trains themselves run in a few minutes between Terminals 2/3 and Terminal 5. The real time cost is the security re-screen at your new terminal, so many travellers allow at least 45 to 60 minutes overall, more for Terminal 4.
Do I need to go through security again when I change terminals?
Yes, in almost all cases. Even connecting passengers on a single ticket normally clear security again at the new terminal.
Is Terminal 4 harder to reach than the others?
Yes. Terminal 4 sits on a separate branch, so reaching it from Terminals 2, 3 or 5 usually needs a change of train, either at Heathrow Central or Hatton Cross, adding time compared with the direct T2/3-T5 route.
What if I have two separate flight tickets rather than one connecting itinerary?
You are not treated as a connecting passenger. You will need to clear immigration, collect baggage, and go through check-in, bag drop and security again, which takes considerably longer than a same-ticket transfer, so check your airline's guidance and allow generous time.
Can I walk between Terminal 2 and Terminal 3?
Yes, they are linked by an underground walkway with moving walkways, so no train is needed for that specific transfer.