We’d last covered the London based lockers a little over a month ago. The local name for the locker service will be “Click & Collect”, and they’re going to function much like the US based service. The lockers can be found at malls in and around London, but perhaps the easiest way to find them would be to look under shipping options on Amazon.co.uk. They’re only shown to customers who are reasonably expected to use them according to those who have tested the US lockers.
While I have no direct info on how the UK lockers work, the US service was relatively straightforward. The customer is offered the lockers as a shipping destination during checkout. If selected, the package will be delivered there. When it arrives, the service will email a 6 digit code to the customer. The recipient can get the package by typing the code into the keypad near the locker.