You can travel between all four Heathrow terminals for free, using the London Underground, the free inter-terminal train, or the free H30 bus, as long as you touch in with a contactless card or Oyster, or collect a free train transfer ticket at the station. There's no need to book, and most transfers take 5 to 15 minutes plus walking time within terminals.
This matters most if you're self-connecting, meaning you've booked two separate tickets that require you to land at one terminal and depart from another, rather than a through-connection on one booking. If that's your situation, it's worth reading this alongside our guide on connection times at Heathrow and whether you need to collect your bags on a connection.
The three ways to move between terminals
London Underground (Piccadilly line)
The Piccadilly line calls at Heathrow Terminals 2 & 3, Terminal 4, and Terminal 5, as well as Hatton Cross just off the airport. Trains run roughly every 10 minutes, and every 5 minutes on the short hop between Terminals 2 & 3 and Hatton Cross. You'll need a contactless card, Oyster, or other accepted ticket to touch in and out of the gates, even though the transfer itself is free, since the gates need something to activate them.
Free inter-terminal train
A dedicated train service connects Terminals 2 & 3, Terminal 4 and Terminal 5, running roughly every 15 minutes to Terminal 4 and at least every 15 minutes to Terminal 5. This train is separate from the Underground and from the Heathrow Express or Elizabeth line services. If you don't have a contactless card or Oyster, you can collect a free train transfer ticket at the station to use the gates, though note this ticket only works for the inter-terminal train, not the Underground.
Free H30 bus
The H30 bus runs free of charge between Terminal 4 and Terminal 5 via the airport's cargo area, roughly every 20 minutes, with extra early morning departures also serving other points around the airport. No ticket or card is needed to board the H30, it's free for anyone to use.
Terminal 2 and Terminal 3
Terminals 2 and 3 are close enough to walk between using connecting subways, a walk of around 3 minutes according to Heathrow's own transfer map, so you often don't need the train or Underground at all for this particular pair.
Comparing your options
| Method | Terminals covered | Frequency | Ticket needed |
|---|---|---|---|
| Underground (Piccadilly line) | T2&3, T4, T5, Hatton Cross | Every 10 min (5 min to Hatton Cross) | Contactless or Oyster to touch in/out |
| Inter-terminal train | T2&3, T4, T5 | Every 15 min (T4), at least every 15 min (T5) | Contactless, Oyster, or free transfer ticket |
| H30 bus | T4 and T5 (via cargo area) | Every 20 min | None, free to board |
| Walking subway | T2 and T3 only | N/A | None |
Which one should you use
If you're moving between T2/T3 and T5, or T2/T3 and T4, either the Underground or the dedicated inter-terminal train works, and both run at similar frequency. The inter-terminal train has the advantage of accepting a free paper ticket if you don't have a contactless card handy, which the Underground gates don't offer in the same way. If you're moving specifically between T4 and T5, the free H30 bus is the simplest option since it needs no ticket at all.
Do I need to check the Heathrow terminal transfer tool first
Heathrow provides an online terminal transfer guide where you select your departure and arrival terminal and it shows the specific route and any current disruption. This is worth checking before you travel if you have a genuinely tight connection, since it reflects any temporary changes to routes or closures that a general guide like this one won't capture in real time.
What if I have reduced mobility
If you have mobility difficulties or need support moving between terminals, Heathrow's assistance service can help plan and support your transfer rather than you navigating it independently. See our guide on booking special assistance at Heathrow for how to arrange this in advance.
Does it cost anything at all
No, moving between terminals by any of these three methods costs nothing beyond touching in and out with a card that would otherwise be charged for a normal Underground journey. Since you're not leaving the free travel zone the airport defines for terminal transfers, no fare is actually deducted, though your card still needs to be presented to open the gates.
All routes and frequencies here were checked 2026 against Heathrow's own transfer guide and free travel map, but always allow extra time and check the live transfer tool if your connection is tight, since frequencies can be reduced late at night or during engineering works.
Frequently asked questions
Is it free to travel between Heathrow terminals?
Yes. The Underground, the dedicated inter-terminal train and the H30 bus are all free for genuine terminal-to-terminal transfers, though you still need a contactless card, Oyster, or free transfer ticket to activate the Underground and train gates.
How long does it take to get between Heathrow terminals?
Most transfers take 5 to 15 minutes on the train or Underground itself, plus walking time within terminals. Terminals 2 and 3 are about a 3 minute walk apart via connecting subways.
Can I walk between any of the Heathrow terminals?
Only between Terminal 2 and Terminal 3, which are connected by walking subways. The other terminals require the train, Underground or H30 bus.
Do I need a ticket for the free H30 bus?
No, the H30 bus between Terminal 4 and Terminal 5 is free to board with no ticket required.
What if I don't have a contactless card for the Underground?
You can collect a free train transfer ticket at the station for the dedicated inter-terminal train, though this ticket isn't valid on the Underground itself.
Where can I check live terminal transfer information?
Heathrow's own website has a terminal transfer tool where you select your from and to terminals to see the current recommended route.