London Marathon 2027 is two days, and you don't get to choose which one

The 2027 race is not the race you have been reading about

Every London Marathon guide currently online describes a single Sunday in April. For 2027 that is wrong, and wrong in a way that changes where you should sleep and when you should book.

The organiser has confirmed a one-off format change: the 2027 TCS London Marathon runs across two days, Saturday 24 and Sunday 25 April, with a hundred thousand participants between them, following the same Greenwich to Westminster route on both. It is being called the Double, and it is scheduled to happen once.

Two consequences follow immediately. The first is that London will absorb close to double its usual marathon weekend demand across the same accommodation stock. The second, and the one that actually governs your booking, is that you do not choose your day.

You are drawn into a day, and it is fixed

Everyone in the ballot was entered into a random draw covering both days. The organiser’s position on changing it is unambiguous: your allocated event day is fixed and cannot be changed. If you are drawn on the Saturday and do not want it, your only option is to decline by not paying.

This creates a booking problem that does not exist in any normal year. A Sunday runner’s critical night is the Saturday. A Saturday runner’s critical night is the Friday. Until the draw resolves, you do not know which one you need — and with a hundred thousand runners competing for the same weekend, waiting to find out is the expensive path.

The practical answer is to hold a refundable booking that covers Friday through Monday and release what you do not need. That sounds like over-booking. Against a field this size in a city this expensive, it is cheaper than the alternative.

The Saturday is a harder race than the Sunday

This is not symmetric. Saturday is time-constrained because the roads have to reopen, and the organiser has been explicit about what that means.

Saturday is likely to start at 09:00, with the finish line closing at 17:30 — a maximum of 7 hours 45 minutes. The organiser goes as far as telling anyone who believes they will take longer not to pay for a Saturday place at all. Sunday is likely to start at 09:30, and its secondary finish line in Green Park stays open until just before midnight.

If you are drawn on the Saturday, you are running a marathon that starts earlier and gives you less time. Everything about your accommodation should be biased towards removing risk from the morning rather than optimising the afternoon.

Your bib colour decides your station

London’s other constraint is one that catches first-timers every year, Double or not. There is no single start. There are five assembly areas, identified by bib colour, and each is tied to a specific station.

Blue and Green assembly areas are roughly a ten-minute walk from Blackheath. Pink is about ten minutes from Maze Hill. Red is a twenty-minute walk from Greenwich. Your registration email tells you which area you are in, what time to arrive, and which trains to take, and none of that is a suggestion.

The booking implication is that “stay near Greenwich” is not useful advice. What you want is to be near a line that serves your station, not near the destination. South Bank and London Bridge do this well for all three stations, which is why they appear in the zone comparison below despite being neither start-side nor finish-side.

There is one genuine trap in the published transport detail. On race Sunday, DLR services start at about 05:30 from Tower Gateway and Lewisham, but only at about 07:00 from Bank and all other DLR routes. A hotel near Bank looks superbly connected on a map and is useless to you before seven in the morning.

Free travel, and the thing it does not cover

Participants travel free to the start on Southeastern services from London stations, and on the DLR, Elizabeth line, Underground, Overground and buses. You present your bib rather than tapping in or out. Spectators are explicitly not included, which is worth knowing before you promise anyone a lift.

This is genuinely generous and it removes cost from the equation. It does not remove risk. Free travel on a crowded line still leaves you dependent on that line running, on a morning when tens of thousands of people are making the same journey to three small suburban stations.

Your bag crosses London without you

Unlike Boston, where nothing is transported from start to finish, London runs a numbered baggage lorry system. You attach your bib-numbered sticker to your official kitbag, hand it to the lorry matching your number at your assembly area, and collect it at the finish from the same lorry number.

There is one exception worth checking against your own bib: there is no bag drop at all in the Green assembly area. Team Green participants drop a small bag at the finish area in St James’s Park the day before instead.

The accommodation consequence is a good one. Because your bag reaches the finish, a finish-side hotel is more workable in London than the equivalent in Boston. You are not carrying anything across the city, and what you want after the race arrives where you end up.

The Event Pack problem

You cannot run without your Event Pack, and you cannot get it on race morning. Collection is at ExCeL London, in the Docklands, and closes at 17:30 on the Saturday.

In a normal year that is an errand. For the 2027 Double it is a scheduling conflict: ExCeL sits well east of both Greenwich and Westminster, and Saturday runners are collecting a pack on a day when the race is already happening. Build that journey into your plan explicitly, and if you are drawn on the Saturday, check the organiser’s confirmed arrangements rather than assuming the 2026 pattern holds.

Three anchors, and no bed that serves all of them

Most guides describe London’s geography as start-versus-finish. It is actually a triangle, and we measured it.

Leg	Straight-line distance
Blackheath start → The Mall finish	10.19 km
ExCeL (Event Pack) → Blackheath start	4.51 km
ExCeL (Event Pack) → The Mall finish	11.02 km

Three fixed places, spread across roughly eleven kilometres of London, and every one of them has a deadline attached: the pack closes at 17:30 Saturday, the start lines close at 11:30, and the finish is where your kitbag ends up.

Set the candidate neighbourhoods against the two race-day anchors and the tradeoff is stark:

Zone	To Blackheath start	To The Mall finish
Greenwich	1.49 km	9.07 km
Canary Wharf	4.21 km	7.65 km
Tower Bridge / South Bank	6.85 km	3.75 km
Westminster / St James’s	9.76 km	0.69 km

Nothing is close to both. Greenwich is a fifteen-minute walk from the start and a transit journey from the finish; Westminster is the exact inverse at 690 metres from The Mall and nearly ten kilometres from Blackheath. There is no Logan Square here, no midpoint that quietly solves it, the two ends are ten kilometres apart and London has put a river and a rail network between them.

That is why this guide recommends booking towards a line rather than a landmark. The only zone that compresses both numbers at once is the South Bank / Tower Bridge corridor at 6.85 and 3.75 kilometres, not close to either, but on the trains that reach all three assembly stations, and walkable back from the finish. Being on the right rail line is worth more here than being near anything.

Canary Wharf deserves a mention for one reason only: at 4.21 kilometres from the start it is the closest of the central options to Blackheath, and it is the nearest of them to ExCeL. If you are drawn on the Saturday and have to collect a pack and run in the same weekend, that combination has real value.

London absorbs the marathon, the problem is not supply

This is worth saying plainly, because it is the opposite of Boston and Valencia.

Checked on 4 August 2026, comparing race weekend with an ordinary weekend one week earlier:

	Race weekend 23–26 Apr 2027	Ordinary weekend 16–19 Apr 2027
Properties on Booking.com	5,344	6,926

Seventy-seven per cent of ordinary supply was still available for race weekend. London is simply large enough to swallow a hundred thousand runners without running out of beds, a claim we could not make about Boston, where the continuous race weekend returned zero properties.

Price is a different matter, and it concentrates where you would expect. Taking the same Trafalgar Square properties across both weekends, the median was about 1.8 times the ordinary rate, with the sharpest rise on the properties closest to the finish. One serviced apartment was unchanged. So the premium is real but moderate, and it is a finish-side premium rather than a citywide one.

The practical reading: you are not racing other runners for a room in London the way you are in Boston. You are paying a surcharge for proximity to The Mall, and you can decline to pay it by moving to the rail corridor instead, which this page recommends anyway, for reasons that have nothing to do with price.

One trap in the week after

A caution we found by accident, and it is worth passing on.

Our first attempt at a control weekend used 30 April to 3 May 2027 and returned zero properties across the whole of London. The reason is not the marathon: Monday 3 May 2027 is the UK’s early May bank holiday, the first Monday of the month, and the city was already full.

So if you were planning to stay on after the race and make a week of it, be aware that the weekend immediately following the 2027 Double is a national holiday weekend in the UK, and on the evidence above it books out harder than the marathon weekend does. Extend forwards into the week if you can, not across the following weekend.

How to book against uncertainty

The honest summary is that London 2027 asks you to make an accommodation decision before you have the information you need to make it. Given that:

Hold refundable nights covering Friday to Monday as early as you can. Bias your location towards a rail line serving Blackheath, Maze Hill and Greenwich rather than towards any particular landmark. If you are drawn on the Saturday, weight the morning heavily, because your cut-off is tighter and your margin is smaller. And release the nights you do not need as soon as the draw tells you which they are.

The zones below are ordered on that basis rather than on price or prestige.