Do you use a lot of data? Three offers unlimited 3G data with unlimited tethering. 3G might not sound appealing, but 3G in London is faster than 4G in many parts of the USA. When I go to the UK I use Three, and pay something like $24 a month for unlimited data. It's fast enough that I can tether my laptop and stream 1080p video, torrent files, and do anything else I'd want to do.
Thanks. I hope there are no unreasonable requirements for acquiring or paying for the SIM card as a foreigner.
It's my old iPhone 4 which I had unlocked, so no 4g possible.
Thanks. Yes, mostly data, but not huge amounts of it - I guess around 500MB to 1GB per month. And 3G is ok.
Three sounds pretty good. Hope buying the SIM card as foreigner is no problem as in other countries, or that the payment is possible with foreign credit cards, etc.
You should have no issue obtaining a pay as you go sim as they are free from Network shops.
Lots of people recommending Three on here. My experience is that they are the worst carrier in London. The best prices yes, but you get what you pay for.
Another cheap carrier is giffgaff, where you can get 1GB of data, 500 mins and unlimited texts for £10 per month. Or you could try Ovivo as someone said, but that requires a £20 upfront cost for the SIM.
i can attest to 3. Its cheap, its unlimited, it suits the casual need.