Last updated: August 10, 2026
How long a Heathrow layover you need comes down to whether you change terminals and whether you cross the UK border. For a same-ticket connection in the same terminal, 60 to 90 minutes usually works; a terminal change wants 90 to 120 minutes; an international-to-UK-domestic connection needs 2 to 3 hours; and separate tickets need 3 to 4 hours or more. Here are the real numbers, terminal by terminal.
How Heathrow layover time gets used
The process flow behind most connection buffers at Heathrow.
Arrival
Land and orient
Immigration
Border control if needed
Terminal transfer
Move between gates or terminals
Security
Re-clear if required
Boarding buffer
Aim to reach the gate early
- you are self-transferring
- you have checked bags
- you need to clear immigration
- you must change terminals
Times verified: July 2026.
Quick answer: how long should a Heathrow layover be?
There is no single Heathrow connection time that works for everyone — Heathrow itself says it depends on your route, airline, whether you change terminals and whether you cross the UK border. As a planning rule for 2026: same terminal on one ticket 60–90 minutes, terminal change 90–120 minutes, international-to-domestic 2–3 hours, and separate tickets 3–4 hours or more.
Heathrow layover planning table
| Connection type | Planning minimum | More comfortable | Why the buffer changes |
|---|---|---|---|
| Same ticket, same terminal | 60 to 90 minutes | 90 to 120 minutes | Lowest-friction Heathrow connection if your inbound flight is on time. |
| Same ticket, terminal change | 90 to 120 minutes | 120 to 150 minutes | You take an airside transfer bus and re-clear security at the departure terminal. |
| International to UK domestic (or Ireland) | 120 to 180 minutes | 150 to 210 minutes | You must pass passport control and a facial biometric check before security. |
| Separate tickets, cabin bag only | 180 minutes | 240 minutes | No protected connection if the first flight is late. |
| Separate tickets with checked bags or terminal change | 240 minutes | 300 minutes or more | Treat Heathrow as an arrival plus a fresh departure, not a simple connection. |
These are TripBuffer planning ranges, not airline minimum connection times — your airline sets the official minimum. For your exact flights, use the Layover Calculator.
Heathrow terminals and airside transfers
Heathrow operates four terminals: 2, 3, 4 and 5 (Terminal 1 is closed). Terminals 2 and 3 sit together in the Central Terminal Area — a 5 to 10 minute walk between the buildings, or 20 to 30 minutes once security is added. Terminals 4 and 5 are separate. To move between terminals airside you follow the purple “Flight Connections” signs to an airside transfer bus, which runs between all terminals at least every six minutes.
| Transfer | Airside time (typical) | Notes |
|---|---|---|
| Terminal 2 ↔ Terminal 3 | 20 to 30 minutes (incl. security) | Short walk between buildings; both in the Central Terminal Area. |
| Terminal 3 ↔ Terminal 5 | 20 to 30 minutes | Airside transfer bus; longer (35–45 min) if you go landside. |
| Any terminal change | Add a second security screening | Heathrow does not segregate arriving passengers, so you re-clear security at the departure terminal. |
Do you need to pass the UK border on a Heathrow connection?
This is what makes some Heathrow connections faster than others:
- International to international (transit): you stay airside and do not pass UK immigration — only a transfer and a security re-screen. This is why a same-alliance airside connection can work on 90 minutes.
- International to UK domestic or Republic of Ireland: you must present your passport at Passport Control and have a facial biometric taken before security — add time.
- Leaving the airport, or separate tickets: you clear the UK border, reclaim bags and start again as a departing passenger.
What makes Heathrow layovers tighter
- All connecting passengers must go through security again at the departure terminal.
- Separate-ticket travellers face arrival formalities, baggage reclaim, check-in, bag drop and security a second time.
- Terminal changes add airside-bus and walking time even when the transfer is straightforward.
- International-to-domestic journeys add passport control and a biometric check before security.
Worked example: an international arrival connecting to a UK domestic flight
Scenario: You land at Terminal 3 at 7:00am from Dubai on one ticket, connecting to a domestic flight from Terminal 5 (for example to Edinburgh).
- Off the plane and walk to Flight Connections: ~15 min → 7:15
- Passport Control + facial biometric (UK border for a domestic onward): ~30 min → 7:45
- Airside transfer bus T3 → T5: ~25 min → 8:10
- Security screening at T5: ~20 min → 8:30
- Walk to gate and settle: ~15 min → 8:45
Total used: about 1 hour 45 minutes. A departure before roughly 8:45–9:00am would be tight, which is why we suggest a 2 to 3 hour buffer for international-to-domestic connections. A pure international-to-international transit (no passport control) would be faster.
When 2 hours at Heathrow feels enough — and when it does not
2 hours can work
One-ticket international-to-international transit, same-terminal journeys and airlines used to Heathrow connections can make 2 hours workable when the inbound flight is on time.
2 hours can feel tight
Terminal changes, late arrivals, long walks, international-to-domestic routing and heavy congestion can turn 2 hours from comfortable into stressful very quickly.
Separate tickets are different
On separate tickets you are not protected like a through passenger. That is why TripBuffer uses much larger buffers for self-transfers at Heathrow.
Can you leave the airport during a Heathrow layover?
Usually only if you have a genuinely long buffer. Heathrow does not recommend leaving the airport even on a long wait, and says that if you do leave you should return like a normal departing passenger: about 3 hours before long-haul departures and 2 hours before short-haul flights. If that is your plan, use our dedicated Can I Leave Heathrow During a Layover? guide, and on separate tickets pair it with the Heathrow Self-Transfer Guide. For overnight connections, see How to Plan an Airport Hotel Stopover.
Methodology and official references
These Heathrow ranges are TripBuffer planning ranges, not airline minimum connection times. They combine Heathrow’s published connections process, its guidance for self-connecting passengers, and the practical friction of terminal transfers, security and the UK border. Actual waits vary by time of day and season, so always check your airline’s connection rules before you travel.
- Heathrow — connecting flights guide
- Heathrow — travel between terminals
- British Airways — Heathrow flight connections
Last verified July 2026. Minimum connection times are set by each airline; immigration and security waits change by the hour.
Frequently asked questions
What is the minimum connection time at Heathrow?
Airlines generally set a Heathrow minimum connection time of 60 to 90 minutes for a same-terminal connection and 90 to 120 minutes when you change terminals. Self-connecting passengers on separate tickets should allow 3 to 4 hours.
Is 90 minutes enough for a Heathrow connection?
It can be enough on one ticket if you stay in the same terminal and your inbound flight is on time, but it is not a comfortable buffer for a terminal change or separate tickets.
Is 2 hours enough for an international connection at Heathrow?
Two hours is often workable for an international-to-international transit on one ticket, but it becomes much less comfortable if you change terminals, go from international to UK domestic, or face any disruption.
How long does it take to transfer between Heathrow terminals?
Airside, allow about 20 to 30 minutes between Terminals 2 and 3 or between Terminals 3 and 5, including the walk and transfer bus. A terminal change also means re-clearing security at the departure terminal.
How much layover time do I need at Heathrow on separate tickets?
Allow at least 3 hours with cabin bags only, and 4 hours or more if checked baggage, a terminal change or border formalities are involved. On separate tickets there is no protection if the first flight is late.
Can I leave Heathrow during a layover?
Only with a genuinely long layover. Heathrow says if you leave the airport you should return like a normal departing passenger, which means being back about 3 hours before long-haul departures and 2 hours before short-haul flights.
Reviewed by Muhammad Umar Khan
Founder and editor of TripBuffer. Reviewed against official airport, airline and transport-provider information. For our research standards, see the Editorial Policy.