I was recently in the UK, and did a bit of research before choosing a SIM card for my Nexus One.
In the end, I choose T-Mobile because it was cheaper - I didn't want to have to pay for a SIM card. The downside was that t-mobile block SIP packets, so I could not use SIP Droid on the N1.
UK Network Top-ups
When you get a SIM card in the UK, you also get a mag-stripe card for top-ups. You hand over (say) £10 to the cashier with the top-up card. The card is swiped through the till or credit card machine, and the £10 gets credited to your phone automatically. No need to key in codes from the phone.
Most supermarkets, petrols stations, and newsagents will be able to do a top-up.
VodaFone
Getting a SIM
Walk into any VodaFone, Carphone Warehouse, or The Link store and purchase one. Pay cash, get SIM.
Prices
The SIM only price was £5.
Data prices are:
- 50p per day up to 25MB
- £7.50 for 30 days up to 250MB
3
Getting a SIM
Walk into any 3 Store, Carphone Warehouse, or The Link store and purchase one. Pay cash, get SIM.
Prices
The SIM only price was free with a £10 top-up.
Data prices are:
- 150MB free per topup (I think)
- £10 for 1GB
- £15 for 3GB
- £25 for 7GB
The 3 credit expires after 30 days.
O2
Getting a SIM
Walk into any O2, Carphone Warehouse, or The Link store and purchase one. Pay cash, get SIM.
Prices
The SIM only price was £5.
Data prices are:
- £2.00 for 250M (24 hours)
- £7.50 for 1GB (7 days)
- £15 for 3GB (30 days)
I think that O2 pre-paid credit expired after 60 days.
T-Mobile
Getting a SIM
Walk into any T-Mobile, Carphone Warehouse, or The Link store and purchase one. Pay cash, get SIM.
Prices
In a T-Mobile store, the SIM was free. Carphone Warehouse was looking for £5.
There's a ceiling of £2 per day with data usage, with no particular limit.
You can also bulk buy "x days of internet usage". T-Mobile call these "internet boosters".
- £2.50 for 5 days
- £5 for a month
- £20 for 6 months
Credit will expire after 6 months of no use, but a text message or top-up will refresh the expiration date.