UK hub · published · checked
LondonLHR · London Heathrow Airport
London layover guide from Heathrow: the Elizabeth line, a single sight, and the ETA you need before you fly if you will pass the border.
- Into the city
- Elizabeth line from every terminal. Heathrow Express is 15 minutes to Paddington from Terminals 2 and 3.
- Best window
- A midday arrival and a flight that is not at 07:00
- Watch-out
- An ETA is required for most non-visa nationals before boarding, if they will pass passport control. London does not do two districts.
- Entry
- Not Schengen. British and Irish citizens need no ETA. Other non-visa nationals need one before they fly if they enter. Airside transit is the exception.
Three lengths
One turn of the clock
24 hours
London punishes the traveller who tries to see it. Twenty-four hours is the Tower, or the Eye and a boat, and a hotel on the Elizabeth line.
A night in the city
48 hours
Forty-eight hours is a night in London and still only one district. The second day is a walk or a boat, not a second city.
A long weekend on a ticket
72 hours
Seventy-two hours is a weekend, not a tour of southern England. The third day is Greenwich by boat, or a second walk, or a museum you enter on time and leave on time.
Also on this hub
- Hotels
Boring is the aim. A famous postcode that strands you is the mistake.
- Activities
London is full of tickets. A layover wants one. The boat is the one that forgives a late start.
- Airport to city
Both airport railways work. The mistake is the Piccadilly line with a suitcase, or a taxi that sits on the M4 while the train leaves without you.
- Entry
The UK is not in Schengen. ETIAS does not apply. The document that does, for most visa-exempt visitors, is the ETA, and it has to exist before the airline will board you.
Questions
Is London realistic on a 24 hour layover from Heathrow?
Yes, as one place. The Elizabeth line runs from Terminals 2, 3, 4, and 5 into the centre. Use the day for the Tower of London, or for the London Eye and a boat, not for both plus a museum and a West End show. A private Heathrow tour is about six hours and it is priced like a private car.
Do I need an ETA to leave the airport?
If you pass UK passport control, yes, unless you are British or Irish or you already hold a visa or other permission. From 25 February 2026 carriers refuse boarding to non-visa nationals who do not have an ETA or another valid permission. An ETA is not a visa and it does not itself admit you. The April 2026 Home Office factsheet put the fee at £20 and said the fee is kept under review, so confirm the amount on gov.uk. Airside transit at Heathrow, without passing passport control, does not currently require one.
Elizabeth line or Heathrow Express?
Express if the hotel is at Paddington and you want the 15 minutes from Terminals 2 and 3. Terminal 5 is a few minutes more. Terminal 4 means a change onto the free transfer at Terminals 2 and 3. The Elizabeth line is the default for everywhere else, because it continues through the centre and it stops at all four terminal stations. The Piccadilly line is the slow one with a suitcase.
Can I add Windsor, Bath, or Oxford?
Not on 24 hours, and not as a bonus on 48. Windsor is the only one that belongs in a conversation about 72 hours, and only as a swap for a London day. Bath and Oxford are holidays. This layover is the Tower, the river, or a single walk.