Sim card in London?

[Andylion]

I forgot that there was a travel board here on MN, so I posted this on chat by mistake. Apologies for posting in two different sections.

I will be visiting London in late May and would like to be able to use my cell phone.
This company, "3", is recommended on TripAdvisor. Has anyone ordered a sim from their website? Or, I suppose the question should be, do any of you have relatives who have visited England who have used them?

Three is a popular mobile phone service with decent coverage - you should be fine using them in London.

Thanks, @OutsideContextProblem. I'll give it a try.