The British Museum announced no additional 2026 capacity by 10 August; the 2026 run stayed sold out, with the Guardian reporting on 15 August that hotel packages were the only route in.
The capacity market resolves YES only on an official British Museum announcement (press release or britishmuseum.org ticketing page) of additional 2026 entry capacity — new slots, a formal returns scheme, or extended opening hours for the exhibition; the October release for 2027 dates does not count.
We looked for big exhibitions whose tickets sold out completely. Such sellouts are rare, so the cases are well known. In each modern case the museum found room for more visitors within weeks. How it did so was different every time, from tickets sold on the morning of the visit to opening late into the night.