Click the diagram to make it larger.
I made this diagram last year and thought I’d update and publish it here for anyone trying to figure out the complexities of the UK’s mobile network operators. It shows when each mobile network was started and who owns it today, Vodafone being the only network that’s still British owned. It also shows the mobile virtual network operators, such as Tesco Mobile, and whose network infrastructure they use. The red stars show network ranking based on the number of subscribers. The merger of T-Mobile and Orange gave Everything and Everywhere the largest market share overnight.
Good luck choosing a mobile network for your new iPhone or iPad Wi-Fi + 3G!
Incidentally, this diagram was made with OmniGraffle, my diagramming tool of choice.