Six things in London genuinely sell out, and four of the most famous attractions never do because they are free and let you walk in. Book, in this order: your ETA, your hotel, the Warner Bros. Studio Tour, a Big Ben tower tour, Sky Garden, and any West End show you have actually set your heart on. Everything else can wait.
The trap is not under-booking. It is spending a fortnight of evenings reserving timed slots for things that do not need them, then arriving with a schedule so tight that a delayed train ruins the day. London is a city where the four biggest museums are free and you can turn up at the door.
What follows is a timeline, from three months out to the night before, with what has to be locked in at each stage and why. It assumes a trip of a few days; our guide for first-time visitors covers the wider planning.
Book ahead or turn up: the short answer
- Must be booked, no exceptions
- Warner Bros. Studio Tour. No tickets are sold on the day
- Released on a fixed schedule
- Big Ben tower tours, second Wednesday of the month at 10am, three months ahead
- Released weekly
- Sky Garden's free tickets, every Monday morning, three weeks ahead
- Buy before you fly or not at all
- A Visitor Oyster card. It cannot be bought in London
- Cheapest early
- Rail Advance tickets, up to 12 weeks ahead; Heathrow Express advance singles from £10, bought 30 or more days ahead
- Never needs booking
- The British Museum, the National Gallery, the Natural History Museum, Sir John Soane's Museum
- Allow three working days
- Your ETA, at £20 a head
- Book the night before
- A theatre seat from the on-the-day release, and dinner on a Friday
Three months out: the ones with a release date
Two bookings in London work on a published schedule rather than on availability, and if you miss the window you wait a month.
The Elizabeth Tower tour, which is what people mean by going up Big Ben, releases tickets three months in advance on the second Wednesday of every month at 10am. It costs £55 for an adult and £35 for ages 11 to 17, the minimum age is 11, it is 334 steps and there is no lift. One person can buy a maximum of eight tickets. International visitors can book it; only the free MP-arranged tours of Parliament are restricted to UK residents. Our page on Big Ben and the Elizabeth Tower has the rest.
The Warner Bros. Studio Tour at Leavesden is the one attraction near London where turning up is simply not an option: every ticket must be pre-booked and none are sold on the day. Adult entry is £58.50 in 2026 and £61.00 in 2027, with children aged 5 to 15 at £47 and £48. A visit averages about three and a half hours, and the shuttle bus from Watford Junction is included in the ticket. Our guide to the Warner Bros. Studio Tour explains the journey.
If your trip includes a ballot event, three months is also too late. The Wimbledon public ballot for 2027 has already closed, and the London Marathon ballot for 2027 was drawn in July 2026. Those are annual deadlines, not booking windows.
Photo: DiscoA340 · CC BY-SA 4.0 · Wikimedia Commons · resized
Two months out: flights, hotel, and the paperwork
Your Electronic Travel Authorisation costs £20 a person including babies, and GOV.UK asks you to allow up to three working days for a decision. Apply when you book the flight. There is no advantage in waiting and no way to buy speed.
Hotels are the item where the calendar matters most to your budget rather than to availability, and our page on when to book a London hotel sets out how the pricing moves. Book something you can cancel if your dates are not fixed, and read the cancellation terms rather than the badge on the booking page.
Rail tickets for day trips out of London go on sale up to 12 weeks ahead, and Advance singles are the cheapest fares on most routes. They are tied to one specific train, they are not refundable unless that train is cancelled or delayed and you do not travel, and a change costs up to £10 plus any difference in fare. Our guide to buying UK train tickets explains when the saving is worth the inflexibility.
A Visitor Oyster card is the one thing you cannot buy once you arrive. TfL sells it only for delivery to your home address before you travel, at £10.50 plus postage with the credit you choose. It is not necessary: a contactless bank card does the same job with the same fares and caps. But if you want one, it has to be ordered now. Our page on whether the Visitor Oyster card is worth it weighs it up.
Three weeks out: Sky Garden and the theatre
Sky Garden is free, but only at a particular moment in the week. The release is on Monday mornings, bank holidays excepted, and it covers the whole of the week three weeks later. The free hours themselves are 10am to 6pm on weekdays and 11am to 9pm at weekends; a ticket names a time slot and gives you an hour inside. Spare capacity is sometimes let in at the door, though not after 5pm on a weekday, and nobody under 16 is admitted after 6pm on a weekday or 9pm at a weekend.
One warning applies in September 2026: a lift at Sky Garden has been out of service with reduced capacity, so check the current position before you build an evening around it. Our page on Sky Garden and how to book carries the detail and the alternatives if you miss the release.
For theatre, three weeks is about right for a show you specifically want, and far too early for a bargain. Before you book, check that the production you have read about is still the production that is running: the two-part version of one of the West End's biggest shows finished on 20 September 2026 and a single-part version opens on 9 October, with the theatre dark between the two. Our guides to West End theatre and cheap theatre tickets explain which route suits which kind of trip.
One week out: the things worth a reservation
Dinner is the real one. London's better restaurants fill for Friday and Saturday evenings, and a table at 7.30pm on a Saturday is the hardest thing in this article to get at short notice. A reservation a week out solves it; so does eating at 6pm or 9.30pm, and so does choosing from the list of London restaurants that do not take bookings, where the queue replaces the diary.
A few museum experiences inside free museums need their own booking, and a week is not always enough. The V&A East Storehouse is free and needs no booking to walk in, but its Order an Object appointments, where a member of staff brings a specific item out of the store for you, must be booked at least two weeks ahead. Our page on V&A East Storehouse explains what it is.
If you are travelling on Eurostar, no separate booking is needed but the timing is not what most guides say: the recommended arrival at St Pancras is 75 minutes before departure in Standard and Plus, and gates close 30 minutes before the train goes. Our guide to Eurostar from London to Paris has the process.
The four that never sell out
These are the attractions visitors most often waste a week's planning on, and they are all free and all walk-in.
| Attraction | Booking | What to know instead |
|---|---|---|
| The British Museum | Not needed; walk-up entry allowed | Open 10.00 to 17.00, Fridays to 20.30. Free, with paid special exhibitions |
| The National Gallery | Not needed; an optional free ticket gives faster entry | Daily 10am to 6pm, Friday to 9pm. The Sainsbury Wing is now the main entrance |
| The Natural History Museum | Not needed; a free ticket guarantees entry | Daily 10.00 to 17.50, last entry 17.30. Queues at weekends and in school holidays |
| Sir John Soane's Museum | None available; there are no time slots at all | Free, Wednesday to Sunday 10am to 5pm. You may have to queue at the door |
The Science Museum is the exception that proves the rule: it is free but now asks visitors to pre-book a free ticket, while its own FAQ confirms that walk-up entry is available daily. Tate Britain says plainly that there is no need to book. Our guide to free museums in London lists the rest.
Check what is closed before you book anything in the last quarter of 2026. The Royal Observatory at Greenwich closes on 2 November 2026 until summer 2027. The London Museum's new West Smithfield site is opening on 28 November 2026, not open now. Buckingham Palace's summer opening ends on 27 September 2026 and the 2027 dates have not been published. These are the four plans most often made from an out-of-date article.
The night before, and the morning itself
Two useful things happen at the last minute. The Official London Theatre Ticket Booth in Leicester Square releases its on-the-day tickets at 12.01am daily, online as well as at the window, and the booth itself opens 10.30am to 6pm Monday to Saturday and 11am to 4pm on Sunday. Shakespeare's Globe also puts a small batch of £5 standing places online at 11am each Friday, for performances in the week that follows.
The other last-minute job is checking that transport is running. Look at TfL's status page the night before and again at breakfast, because weekend engineering work closes sections of line that the maps do not show. Planned closures are published in advance on the same page, and they are far commoner than strikes.
Finally, do not book a timed slot for the morning you land. Immigration, baggage and the journey in are all outside your control, and a missed timed ticket is money gone. Our guide to your arrival day in London makes the case for treating the first afternoon as unstructured.
Frequently asked questions
What do you actually have to book in advance in London?
The Warner Bros. Studio Tour, which sells nothing on the day; the Elizabeth Tower tour, released monthly on a fixed schedule; Sky Garden's free timed tickets; a specific West End show; a Saturday-night restaurant table; and your ETA, which needs up to three working days. Everything else can usually be arranged in London.
Do I need to book the British Museum?
No. Entry to the permanent collection is free and walk-up entry is allowed, with the museum open from 10.00 to 17.00 and until 20.30 on Fridays. Paid special exhibitions are a different matter and popular ones do sell out, so book those separately.
How far in advance do Sky Garden tickets go on sale?
Free tickets are released every Monday morning, excluding bank holidays, for the week three weeks later. Each ticket covers a stated time slot with an hour's limit. Walk-ins are possible if there is space, but not after 5pm on weekdays.
Is it cheaper to book London attractions in advance?
Often, and sometimes by a lot. Several paid attractions charge more at the door than online, and rail Advance tickets and Heathrow Express advance singles are much cheaper bought weeks ahead. Free attractions cost the same whenever you go, which is why they belong at the flexible end of your plan.
Should I buy a London Pass before I travel?
Only if you have worked out that it saves you money on the specific attractions you intend to visit, which depends heavily on how many paid sights you do in a day. Our page on whether the London Pass is worth it does that arithmetic with current prices.
Sources
- UK Parliament - Elizabeth Tower (Big Ben) tour (checked September 2026)
- Warner Bros. Studio Tour London - Tickets (checked September 2026)
- Sky Garden - Booking (checked September 2026)
- Sir John Soane's Museum - Your visit (checked September 2026)
- The National Gallery - Plan your visit (checked September 2026)
- Natural History Museum - Visit (checked September 2026)
- Society of London Theatre - The Official London Theatre Ticket Booth (checked September 2026)
- National Rail - Advance tickets (checked September 2026)