I bought a 20GB O2 SIM card for £20 per month before cash back, £8 per month after. 12 month contract. Service was good and I think this was a well priced offer in the market. Only two bits of feedback for improvement: 1. This was a Black Friday special deal but I notice that (of course) the price is still the same today... so maybe next time I will wait... 2. When I bought a similar SIM card through mobiles last year there was an automatic cash back option. This was not available this year which means that I have to go through the cumbersome process of making individual claims. Would prefer to have the auto cashback even though this is at a lower level.