Terminal 2 and Terminal 3 are linked by a 10-minute covered walkway. Terminals 4 and 5 need the free Elizabeth line or Heathrow Express inter-terminal transfer, each around 5 to 7 minutes on the train itself. Heathrow's own guidance works to a minimum connection time of 1 hour for a same-terminal transfer and 1 hour 30 minutes if you are changing terminals; separate tickets need much longer. Checked 2026.
How to physically move between terminals
| Route | Method | Approx. time |
|---|---|---|
| T2 to T3 | Walk (covered, step-free underground walkway) | About 10 minutes |
| T2/T3 to T5 | Free Elizabeth line or Heathrow Express | About 5 to 7 minutes on the train |
| T2/T3 to T4 | Free Elizabeth line | About 5 minutes on the train |
| T4 to T5 | Change at T2/T3, or free connecting train | Around 15 to 20 minutes total |
Add walking and security re-screening time to all of these, since the numbers above cover the ride or walk itself, not the full door-to-gate process.
Is it really free?
Yes, for genuine inter-terminal transfers. Transport for London confirms that you can use the Elizabeth line to transfer for free between Terminal 2 & 3, Terminal 4 and Terminal 5: tap your contactless card or phone at the gates and you will not be charged, or pick up a free inter-terminal transfer ticket from a machine in the station if you prefer not to use contactless. The same no-charge principle applies to the Heathrow Express when used purely for an inter-terminal hop rather than a journey into central London.
Minimum connection times
Heathrow's own connecting-flights guidance confirms that a connecting flight may depart from a different terminal to the one you land at, and tells passengers to follow the purple signage through security to their next gate. The specific minimum connection times most consistently reported by travel and industry sources are 1 hour for a same-terminal, single-ticket connection and 1 hour 30 minutes if your connection changes terminals. These are minimums set by the airport and your airline, not comfortable planning times, and only apply if both flights are on one ticket, since your baggage is then transferred for you and you generally do not need to clear UK immigration.
If you have booked two separate tickets rather than one connecting itinerary, you are not technically a "connecting passenger": you will need to clear immigration, collect and re-check your bags, and go through security again as if starting a fresh journey. Airlines commonly recommend at least 3 to 4 hours in this situation, and British Airways' own guidance specifically recommends a minimum of 4 hours for separate tickets.
Self-connecting: what changes
Self-connecting (booking two flights separately, sometimes on different airlines) removes any protection if your first flight runs late, since there is no single ticket linking the two journeys. Build in a longer buffer than the airport minimums above, particularly if your itinerary also involves a terminal change, since you will be doing the walk or train transfer landside, with a full security re-screen, rather than the faster airside route available to single-ticket passengers. See leaving Heathrow during a layover if you are considering going landside during a long gap between flights.
Practical tips for a terminal change
- Follow the purple signs if you are a single-ticket connecting passenger staying airside; follow yellow signage if you are clearing immigration or starting a fresh journey.
- All connecting passengers go through security again at the departure terminal, even on a single ticket, so budget time for this regardless of connection type.
- Large electronics and liquids up to 2 litres can stay in your cabin bag when connecting through UK security, per Heathrow's guidance.
- Check your boarding pass or the information screens for your departure terminal if you are unsure, since it is not always the same terminal you arrived at.
Frequently asked questions
How long does it take to transfer between Heathrow terminals? About 10 minutes to walk between T2 and T3, or around 5 to 7 minutes on the free Elizabeth line or Heathrow Express to reach T4 or T5, plus walking and security time either side.
Is it free to travel between Heathrow terminals? Yes. Tap in and out with contactless on the Elizabeth line or Heathrow Express for a genuine inter-terminal transfer, or collect a free transfer ticket from a station machine.
What is Heathrow's minimum connection time? Commonly reported as 1 hour for a same-terminal connection and 1 hour 30 minutes for a terminal change, for passengers on a single through-ticket. Separate tickets need considerably longer, often 3 to 4 hours or more.
Do I need to go through security again when changing Heathrow terminals? Yes, all connecting passengers are re-screened at the departure terminal, even on a single ticket.
What if I booked two separate tickets instead of one connecting itinerary? You are not a protected connecting passenger. You will need to clear immigration, collect and re-check baggage, and pass security again, so plan for at least 3 to 4 hours between flights.
Which Heathrow terminals are linked by a walkway? Only Terminal 2 and Terminal 3, via a covered, step-free underground walkway taking about 10 minutes.
More: Overview, Public transport, Routes, FAQs.