Recommendation for data SIM in UK

[wco81]

Originally Posted by NFH

As I said before I suggested GiffGaff, O2 may be your best bet.

With regard to coverage, it's worth understanding the frequencies of each network:

• Vodafone - 900, 1800 & 2100
• O2 - 900, 1800 & 2100
• Orange - 1800 & 2100
• T-Mobile - 1800 & 2100
• Three - 2100

Lower frequencies penetrate buildings much better, so Vodafone and O2 have a slight advantage. However, Orange and T-Mobile recently merged and you can now roam between both networks free of charge, meaning you get two networks' coverage as a customer of just one network. Consequently coverage on these two is arguably better now than Vodafone or O2. Avoid Three, which only has 3G coverage; everyone I know on Three complains about coverage and lack of signal.

Based on this, I joined giffgaff and PM'd a member to see if he'd ship a SIM to me in the US. Hoping the O2 network is good.

Otherwise, I guess I'd look for T-Mobile or Three when I arrive in London.