The 90-night rule limits whole-property short-term lets in London to 90 nights per calendar year without planning permission. The restriction is set out in the Deregulation Act 2015 and applies to entire-property listings only. Airbnb automatically enforces the cap and will block bookings once the limit is reached. Other platforms such as Booking.com and Vrbo do not enforce it automatically, so hosts must track their own nights if listing across multiple sites. The count resets on 1 January each year.