A six-hour layover at Heathrow buys you roughly ninety minutes in central London, and only if you are allowed through the border. Four hours buys you nothing but a round trip. Ten hours buys a genuine half-day.
The maths is simple once you write it down. From a six-hour gap you lose about an hour to leaving the aircraft and clearing passport control, two hours to being back at your departure terminal in good time, and another hour to the two train journeys. What is left is the part you actually spend in the city.
This page is only about leaving the airport and coming back. If your two flights are on one ticket and you intend to stay inside the secure area, our guide to Heathrow's four terminals covers the purple connection signs, the free inter-terminal transfers and what happens at connection security. What follows starts where that stops: at the arrivals hall door.
Leaving Heathrow on a layover: the numbers
- Minimum gap worth leaving for
- Six hours between landing and departure, on a single long-haul ticket
- Permission needed
- An ETA (£20), a visa, or a passport that needs neither. Airside transit alone is not enough
- Fastest train
- Elizabeth line, Heathrow to Paddington in 28 minutes
- Cheapest train
- Piccadilly line, £5.90 at any hour, about 50 minutes to the West End
- Bag storage
- £10 for up to three hours, £15 for three to 24 hours, per item
- Storage desk hours
- Roughly 05:00–21:00 in check-in areas, 06:00–22:00 in most arrivals halls
First question: are you allowed to walk out of the door?
This is the part that catches people out, and it has nothing to do with time. There are two ways of passing through a UK airport. Airside transit means you never meet an immigration officer. Landside transit means you do, and the moment you go out to the Underground you have entered the country.
The Home Office currently exempts airside transit passengers at Heathrow from the Electronic Travel Authorisation. That exemption disappears the second you decide to see the city. GOV.UK is explicit: you need an ETA if you pass through border control before continuing your onward journey. The ETA costs £20 and covers stays of up to six months, so it is not an obstacle if you sort it out weeks ahead. It is a complete obstacle at 07:00 on the day, because a decision usually arrives within a day but can take up to three working days.
If your nationality needs a visa rather than an ETA, the equivalent is a Visitor in Transit visa, which covers leaving the airport and flying out again within 48 hours. Our page on what visitors need to enter the UK sets out which document applies to which passport. Check it before you build a plan around the idea of a free afternoon.
Walking out of arrivals turns a transit into an entry. Airside passengers at Heathrow do not currently need an ETA. Landside passengers do, and there is no way to buy one at the airport that afternoon.
Photo: Laslovarga · CC BY-SA 4.0 · Wikimedia Commons · resized
The hour you lose before you reach the train
Plan backwards from the aircraft door, not from the scheduled landing time. Taxiing to a stand at Heathrow can take ten minutes on its own, and a widebody takes a while to empty. Terminal 5's arrivals route includes a shuttle train from the satellite piers.
Then comes the border. Heathrow publishes live immigration and security waiting times on its own website, which is worth checking on the morning you fly rather than relying on an average. If you hold a biometric passport from one of the countries whose nationals may use the eGates, you will usually be through in minutes; if you must see an officer, allow considerably longer. Children aged eight and nine became eligible for the eGates in July 2026, which helps families who previously had to join the staffed queue.
If your two flights are on separate tickets you will also be collecting a suitcase from the belt, and that alone can add half an hour. Self-connecting passengers should treat a six-hour gap as a four-hour gap and stay in the building.
Four hours: stay where you are
With four hours between landing and departure, you would need to be back at the terminal within two hours of clearing the border. Subtract the journeys and you have perhaps twenty minutes in the middle of London. That is not a visit; it is a photograph of a station concourse.
Spend the time in the airport instead. Independent lounges at every terminal sell entry by the hour to anyone, regardless of airline or ticket class, and they include food, drink and somewhere to shower; our guide to buying your way into a London airport lounge explains what each one costs and how far ahead to book. If you would rather sleep, the airport hotels we list under where to sleep beside a London runway sell day rooms as well as full nights.
Six hours: one thing, chosen by which station you get off at
Six hours works out at roughly eighty-five to ninety minutes on the ground. The trick is to pick a destination that starts the moment you leave the station, and to accept that you are seeing one thing.
The Elizabeth line is the right train for this. Six trains an hour serve Terminals 2 and 3, four serve Terminal 4 and two serve Terminal 5, so from Terminal 5 you may wait up to half an hour. Paddington is 28 minutes away; the stops after it are the ones that matter.
| Get off at | On foot from the platform | Fits in 90 minutes? |
|---|---|---|
| Paddington | Canal boats at Little Venice, or Hyde Park in about 15 minutes | Yes, as a walk |
| Bond Street | Oxford Street shops; Mayfair squares south of the station | Yes |
| Tottenham Court Road | The British Museum, about five minutes away | Yes, for two or three rooms |
| Farringdon | Smithfield, Clerkenwell, St Paul's in 12 minutes | Yes |
| Liverpool Street | Spitalfields and Brick Lane | Tight, and the return is longer |
Two of those deserve a warning. The British Museum is free and five minutes from Tottenham Court Road, which makes it the obvious layover destination, but it swallows time; our page on how long the British Museum really takes explains what a single hour inside it gets you. St Paul's Cathedral charges for sightseeing entry and closes to visitors well before the last useful train back, so check the day's hours rather than turning up.
The honest alternative is to do nothing ambitious at all. Hyde Park from Paddington, or the streets around Paddington and Bayswater, gives you fresh air, a coffee and a sense of having been somewhere, with almost no risk of misjudging the clock.
Ten hours: a real half-day
Ten hours between landing and departure leaves something close to five and a half hours in the city. At that point you can follow a route rather than pick a single stop. Our one-day itinerary for London is built for a full day, but its first half — Westminster, the river, the South Bank — compresses neatly into an afternoon if you skip the interiors and keep walking.
Set two alarms: one for the moment you must start walking back to the station, and one for the last train that gets you to the terminal on time. Then add twenty minutes to both. Nothing about this plan works if you are the sort of traveller who lingers.
Your bags, and the desks that close before your flight does
You cannot take a suitcase around London comfortably, and on a connection your hold bag may already be checked through. For everything else, Excess Baggage Company runs ten storage desks across the four terminals, in both check-in and arrivals areas. Prices are per item and published by Heathrow.
| How long | Price per item |
|---|---|
| Up to 3 hours | £10 |
| 3 to 24 hours | £15 |
| 24 to 48 hours | £27.50 |
| 48 to 72 hours | £40 |
| After 72 hours | £12.50 per extra day |
The catch is the opening hours. Heathrow lists the check-in-area desks as open 05:00 to 21:00 and most arrivals desks as 06:00 to 22:00. A bag left at 11:00 before a 23:30 departure is behind a shutter when you come back for it. If your return to the airport falls outside those hours, leave the bag in town instead: our guide to left luggage in London lists the staffed and app-booked options near the main stations, most of which open later.
The storage desks shut at 21:00 or 22:00, whatever time your flight leaves. Check the closing time of the specific desk before you hand over a bag, and keep the receipt somewhere other than the bag.
What the round trip costs, and where the daily cap saves you
Every Elizabeth line and Tube journey to or from Heathrow is charged at the peak rate at any hour, which looks expensive until you remember the cap. A single from Zone 1 to Heathrow on the Elizabeth line is £15.50, so two of them would be £31 — except that the Zones 1–6 daily cap of £16.30 applies, and the Elizabeth line to Heathrow counts towards it. Two adults therefore pay £32.60 for the day, including any Tube journeys they make in between.
The Piccadilly line is £5.90 each way at any hour, so a return is £11.80 and never reaches the cap. It takes about fifty minutes from the West End rather than under thirty, which on a six-hour layover is a fifth of your usable time. Paying the extra is usually the better trade. Our comparison of Heathrow Express and the Elizabeth line sets out the third option: fifteen minutes to Paddington for £26 each way, outside the daily cap, but with children aged 15 and under travelling free.
Use one card or one phone for every tap, in both directions, or the cap will not recognise the journeys as belonging to the same day. Our page on Oyster and contactless compared explains why a phone in the morning and a plastic card in the evening are counted as two different travellers. The Elizabeth line guide covers the service pattern in more detail.
If your layover runs through the night
The Elizabeth line and the Piccadilly line do not run all night, and neither does Heathrow Express. What does run is the N9 night bus, between Heathrow Terminal 5 and Aldwych by way of Piccadilly Circus, Trafalgar Square and Charing Cross. At £1.75 a journey it is the cheapest way into town at 03:00, and the slowest by a long way.
This matters most for passengers whose second flight leaves early the next morning. Our pages on reaching an airport outside normal hours and on the night bus network set out which routes run and how long they take. A night in the terminal is rarely a good idea for anyone travelling with children or anyone who needs booked assistance at the airport, because the assistance teams work to flight schedules rather than to people waiting in a concourse.
Frequently asked questions
How many hours do you need to leave Heathrow and see London?
Six hours between landing and your next departure is the realistic minimum, and it gives you about ninety minutes in the centre. With less than six hours you spend the whole gap travelling. With ten hours you have around five and a half hours, which is enough for a proper walk through the city.
Do I need a visa or an ETA to leave Heathrow during a layover?
Yes, unless your passport needs neither. Passengers who stay airside at Heathrow are currently exempt from the ETA, but going through border control counts as entering the UK, so you need an ETA, a transit visa or a visitor visa. The ETA costs £20 and can take up to three working days to be decided.
Where can I leave my bags at Heathrow?
Excess Baggage Company has ten desks across the four terminals, in check-in and arrivals areas. Storage costs £10 for up to three hours and £15 for three to 24 hours per item. Check-in desks generally open 05:00 to 21:00 and arrivals desks 06:00 to 22:00, so a late return may find them closed.
Is the Elizabeth line or the Piccadilly line better for a short layover?
The Elizabeth line, in almost every case. It reaches Paddington in 28 minutes against about fifty minutes on the Piccadilly line, and because it counts towards the Zones 1–6 daily cap of £16.30, a return trip costs an adult that much rather than twice the single fare.
Can I leave the airport if my two flights are on separate tickets?
Yes, and in that case you have to go landside anyway to collect your bag and check in again. Allow at least an extra half-hour for the baggage belt, and treat the gap as shorter than it looks. Many travellers in this position find the detailed route comparisons on our sister site's layover guide to London useful when deciding whether to go at all.
Sources
- GOV.UK – Get an electronic travel authorisation (ETA) to visit the UK (checked September 2026)
- GOV.UK – Entering the UK: layovers and transiting through a UK airport (checked September 2026)
- GOV.UK – Visa to pass through the UK in transit (checked September 2026)
- Heathrow – Luggage storage prices (checked September 2026)
- Heathrow – Excess Baggage Company store locations and hours (checked September 2026)
- Transport for London – Getting to and from Heathrow on the Elizabeth line (checked September 2026)
- Transport for London – Daily and weekly fare caps (checked September 2026)