You can book a hotel in London, United Kingdom using two methods:
Can be done for a hotel which is a participant to the Instant Booking Program. This program allows customers to know immediately if there is an available room for specific dates. When booking has been made and paid, the hotel would know about it immediately.
Proposed for all other hotels, which do not make booking data available on the Internet. To effect such a booking, staff of the booking service will forward the booking to the hotel staff, obtain their confirmation and inform the customer that the booking can be paid. They also make available the payment link.