The transfer process for domain names varies, dependent on the type of domain in question.
UK domains (all domains that end .uk)
Domains ending in .uk require 2 simple steps to be compeleted to transfer them in instantly:
1) Update the Tag to STACK.
2) Complete the transfer via the 20i control panel.
To do these steps:
CentralNIC domains (ending in .uk.com, .gb.com, .eu.com, .uk.net, .gb.net and .eu.net)
GTLD domains (all other domains)