Most people underestimate how long a terminal transfer at London Heathrow takes. Not because the airport is slow, but because they plan around the train time instead of the full process. That is how tight connections turn into missed flights. Most people do not miss connections because Heathrow is confusing. They miss them because they planned using the wrong number. This guide gives you the right one.

At Heathrow, every terminal transfer includes a security re-screen at the destination terminal. That is not optional, and it is not fast during peak hours. The Heathrow Express takes 3 minutes between T5 and T2. The full transfer takes 25 to 40 minutes minimum. Know that difference before you book.

Here is the answer most people are looking for:

What is your transfer?

“I need to get from T5 to T2 or T3” → T5 to T2 or T3 (And The Reverse)

“I need to get from T5 to T4” → T5 to T4 (And The Reverse): The Tricky One

“I need to get from T4 to T2 or T3” → T4 to T2 or T3 (And The Reverse)

“I need to get from T2 to T3 or vice versa” → T2 to T3 (And The Reverse): The Easy One

“I have separate tickets. What does that change?” → Separate Tickets: A Different Process Entirely

“How long do I actually need?” → How Much Time Do You Actually Need?

Transfer Times At A Glance

Critical: these times do NOT include the walk from your arrival gate to the station or bus stop. Every transfer at Heathrow also requires a full security re-screen at the destination terminal. The “Min. Allow” column accounts for all of this: the walk, the wait, the ride, and the security queue. The route times alone are meaningless without that buffer. If you remember one thing: the transfer method is easy. The time comes from everything around it.

How Terminal Transfers At Heathrow Actually Work

Before you get into the specific routes, one thing frames all of them: if you follow Arrivals signs instead of Flight Connections signs after landing, you have just added 45 minutes to your transfer. That single mistake is behind most missed connections at Heathrow that have nothing to do with a delayed flight.

Here is the structure you need to understand.

Heathrow has four active terminals: 2, 3, 4, and 5. Terminal 1 closed in 2015. Each serves a broadly distinct group of airlines, but passengers regularly need to transfer between them.

Every inter-terminal transfer involves three stages: getting to the transit method (bus or train), the transit itself, and a full security re-screen at the destination terminal. The security re-screen is the step most people forget to build into their timing.

There are two ways to make the transfer:

Airside is for passengers on a single ticket with bags checked through to their final destination. Follow the purple Flight Connections signs from the moment you deplane. These lead to the airside Flight Connections bus, which runs every 10 minutes and connects all four terminals. You stay within the secure zone throughout. You will still clear security at the destination terminal, but you do not go through immigration or bag reclaim.

Landside is for separate-ticket passengers, or anyone who needs to collect bags and check in again. You follow the yellow Arrivals signs, collect your bags, clear UK border control, and make your way to the departure terminal to check in and clear departures security. This is a fundamentally different process.

The most important rule at Heathrow: follow purple, not yellow. Once you enter the arrivals hall by following yellow signs, you cannot return airside without clearing UK passport control. That is not a quick detour. It is a full immigration process that adds 45 minutes minimum to any transfer.

Q: Can you transfer between terminals at Heathrow without leaving the airport?

A: Yes. Heathrow has a free airside Flight Connections bus that runs between all four terminals every 10 minutes. Passengers on a single ticket with bags checked through can stay airside for the entire transfer, but they will need to clear a security re-screen at the destination terminal. The full transfer, including walking, waiting, and security, takes 25 to 60 minutes depending on which terminals are involved.

T5 to T2 or T3 (And The Reverse)

This is the most common inter-terminal transfer at Heathrow. BA operates from T5. Star Alliance carriers are at T2. Most oneworld partners and independents are at T3. If you are connecting between British Airways and almost any other major airline, this is your route.

Do not stop anywhere before you reach the bus or the train. That is the instruction. No lounge, no coffee, no shopping. Get to the transfer method first. Everything else can wait if you have time after you check your gate at the other end.

There are two ways to make this transfer:

Airside Route (same ticket, bags checked through): Follow the purple Flight Connections signs after landing. These lead to the airside Flight Connections bus departure point in the connections area. Buses run every 10 minutes. The ride takes 15 to 20 minutes depending on tarmac traffic. On arrival at T2 or T3, you clear a security re-screen before accessing the departures area.

Landside Route (separate tickets or personal preference): Take the Heathrow Express from the T5 underground station to Heathrow Central, which serves T2 and T3. The ride takes 3 minutes. Trains run every 15 minutes. Add a 5 to 10 minute walk on both ends and the transit itself takes 15 to 20 minutes. Then clear departures security at the destination terminal.

One thing worth knowing about the Heathrow Express: inter-terminal journeys between airport stations are free. You do not pay the London fare. Tap in and out with Oyster or contactless and nothing is charged for the terminal-to-terminal hop.

The honest timing: the train ride is 3 minutes. The full transfer, including the walk from your arrival gate to the station, waiting for the train, walking to the terminal at the other end, and clearing security, takes 25 to 40 minutes under good conditions. During the 06:00 to 09:00 morning peak when T5 long-haul flights arrive in volume, the security queue at the destination can add significant time.

If you have less than 60 minutes, move immediately after landing. If you have less than 45 minutes on one ticket, you need to be moving as fast as you can.

Full T5 layout, gates, and security → Heathrow Terminal 5: The Complete Guide

Q: How long does it take to transfer from Terminal 5 to Terminal 2 at Heathrow?

A: Allow 60 minutes minimum for a comfortable transfer. The Heathrow Express takes 3 minutes between stations, but the full journey including walking, waiting, and security at T2 takes 25 to 40 minutes. For connections under 60 minutes, go directly to the Heathrow Express or airside bus the moment you land. Do not stop at the lounge.

By now, you know your route. This is where the differences start to matter.

T5 to T4 (And The Reverse): The Tricky One

This is the transfer that causes most missed connections between major airlines at Heathrow. Most travelers connecting between British Airways at T5 and Qatar Airways or Emirates at T4 do not realize until they are standing at a train platform that there is no direct service. There is not. This is a two-train transfer with a platform change in the middle. The route requires changing trains at Heathrow Central, and that platform change is the bottleneck that eats the time.

Here is the route from T5 to T4:

Take the Heathrow Express from the T5 underground station to Heathrow Central (3 minutes). Exit the Heathrow Express platform and walk to the Elizabeth Line platform. Take the Elizabeth Line one stop to T4 (5 minutes). The walk between platforms at Heathrow Central adds 5 to 10 minutes depending on the crowds.

The route from T4 to T5 is the same in reverse: Elizabeth Line from T4 to Heathrow Central, walk between platforms, Heathrow Express to T5.

Total transit time including all walking and waiting: 30 to 55 minutes. Add security at the destination and the full transfer is 50 to 75 minutes under normal conditions. The train is not your bottleneck. Everything else is.

Allow 90 minutes minimum. If your inbound is running late or it is a peak morning arrival at T5, 90 minutes becomes uncomfortable fast. The platform change at Heathrow Central is where the time collapses if anything runs slightly behind.

T4 sits on the south side of the airport, separate from the central cluster where T2, T3, and T5 are grouped. Most travelers see it on a map and assume it is close to everything else. It is not. That assumption is the thing that causes the misconnect.

Q: How do you get from Terminal 4 to Terminal 5 at Heathrow?

A: There is no direct train between T4 and T5. Take the Elizabeth Line from T4 to Heathrow Central station, then change to the Heathrow Express for one stop to T5. Total journey time is 35 to 55 minutes including walking and waiting, plus security at T5. Allow 90 minutes minimum for a comfortable transfer.

T4 to T2 or T3 (And The Reverse)

This is significantly easier than transferring to Terminal 5, and it is almost entirely absent from existing content online. If you are arriving on a Gulf carrier or any other T4 airline and connecting to a Star Alliance partner at T2 or an independent at T3, this is your route.

Take the Elizabeth Line from T4 directly to Heathrow Central station, which serves both T2 and T3. No train change is required. The journey takes 10 to 15 minutes. Add the walk from your arrival gate to the T4 station, the walk at the other end, and the security re-screen at T2 or T3, and the full transfer takes 30 to 45 minutes.

Allow 45 minutes minimum. If you are arriving during the morning peak and T2 security is busy, 60 minutes is the more comfortable target.

One thing worth noting for anyone building an itinerary: if you have a routing choice that puts your connection at T2 or T3 rather than T5, the T4-to-T2/T3 Elizabeth Line transfer is considerably less complicated than the T4-to-T5 train change. If the connection destination is flexible, this is the easier option.

Q: How do I get from Terminal 4 to Terminal 2 at Heathrow?

A: Take the Elizabeth Line from Terminal 4 to Heathrow Central station, which serves Terminals 2 and 3. No train change is required. Journey time is 10 to 15 minutes. Allow 45 minutes minimum for the full transfer including security.

T2 to T3 (And The Reverse): The Easy One

This is the only transfer at Heathrow where you can relax. If you are stressed about this transfer, you are solving the wrong problem.

T2 and T3 are the closest terminals at the airport. They sit in the central area, connected by an underground pedestrian walkway. Walk time between the buildings is 5 to 10 minutes. For airside transfers on a single ticket, follow the purple Flight Connections signs, and the route may involve a short bus connection, but total time including security is still 20 to 30 minutes.

If you have 45 minutes for a T2 to T3 transfer (or the reverse), you have time. This is not the transfer to stress about at Heathrow. If someone has sent you here worrying about a T2/T3 connection with 60 minutes on one ticket, the answer is: you are fine.

Q: How long does it take to walk from Terminal 2 to Terminal 3 at Heathrow?

A: Terminals 2 and 3 are connected by an underground pedestrian walkway. Walk time between the buildings is 5 to 10 minutes. For airside connections on a single ticket, follow the Flight Connections signs and allow 30 minutes including security.

Separate Tickets: A Different Process Entirely

None of the timings in this guide apply to you.

If your flights are booked on separate tickets and they are in different terminals, the airside transfer process does not exist for you. You must collect your checked bags from baggage reclaim, clear UK border control, make your way landside to the departure terminal, check in for your onward flight, and clear departures security from scratch. That is the full process. It is not a variation on the airside transfer. It is a completely different operation.

The minimum time for this process with checked bags is 4 hours. That figure comes from British Airways own guidance for separate-ticket connections at Heathrow. It is not a conservative estimate from a travel writer. UK border control at peak times can take 30 to 60 minutes on its own. Departures security during the morning wave adds more. Check-in cutoff is usually 60 minutes before departure.

Without checked bags, 2 to 3 hours is a more realistic floor depending on which terminals are involved and what time of day you are traveling.

One additional item: since January 2025, most visa-exempt visitors to the UK (including United States, European Union, Australian, and Canadian passport holders) need a UK Electronic Travel Authorization to enter the country. If your separate-ticket transfer requires you to clear UK immigration, which it will if you have checked bags, you need an ETA before you travel. Confirm current requirements at gov.uk. Airside transit passengers who stay within the secure zone are currently exempt under a temporary exemption introduced in January 2025, but confirm this has not changed before each trip.

Separate Tickets Means A Separate Process. Bag collection, UK border control with 30 to 60 minute queue times at peak hours, a full landside transit, a new check-in, and departures security. The total is 2 to 4 hours depending on bags and terminals. If you cannot build that buffer into the itinerary, the routing is wrong. Reconsider the booking.

How Much Time Do You Actually Need?

Here are the only numbers that actually matter.

T5 to T2 or T3 (and reverse), one ticket, inbound on time:

• 60+ minutes: you are fine.
• 45 to 60 minutes: tight. Move immediately after landing.
• Under 45 minutes: expect problems.

T5 to T4 (and reverse), one ticket, inbound on time:

• 90+ minutes: fine.
• 60 to 90 minutes: very tight. No margin for anything.
• Under 60 minutes: do not plan on making it.

T2 to T3 (or reverse), one ticket:

• 45+ minutes: you are fine.
• 30 minutes: manageable but move quickly.

Separate tickets, any terminals:

• 4 hours minimum with checked bags. 2 to 3 hours without.

One reality check: most missed connections at Heathrow happen because the inbound flight was late, not because the connection time was too short on paper. A 75-minute T5-to-T2 transfer that becomes 30 minutes after a 45-minute delay is a different situation entirely. Buffer is what absorbs what goes wrong.

The variables that eat your buffer fastest: a delayed inbound (the most common cause), peak security queues at the destination terminal during the morning wave from 06:00 to 09:00, the platform walk at Heathrow Central on T4/T5 routes, and not knowing your onward terminal until you land.

If you miss your connection on a single ticket because of an airline delay, the airline will rebook you at no charge. That protection does not exist on separate tickets.

What happens if you miss your connection at Heathrow →

If you have time between connections: which BA lounge to use at T5 → Which British Airways Lounge Should You Use At Heathrow?

Final Thoughts

At Heathrow, the transfer itself is easy. The time comes from everything around it.

Know your route before you land. Know your timing before you book. Follow the purple signs the moment you deplane. Get to the bus or the train before you do anything else.

Everything after that is just waiting for your gate to be assigned.

Back to the complete BA at Heathrow guide → British Airways At Heathrow: The Complete Terminal 5 Guide

Full Heathrow connections guide for BA passengers → Connecting At Heathrow On British Airways: What You Actually Need To Know

Updated for 2026. Check back if Heathrow Express inter-terminal pricing, UK ETA requirements, or terminal assignments change.

Kevin Zanes