Following a tariff overhaul by T-Mobile last month, O2 is the latest network to revamp its monthly contracts. The original home of the iPhone is launching a new SIM-only tariff and updating its ...

A lot of phone networks are offering deals on their SIM-only contracts at the moment, and O2 has joined the long list with an impressive pay-as-you-go SIM-only sale that's on right now. These are some ...

O2's network collapsed overnight, but those signed up to other mobile providers shouldn't feel too smug: the outage caused carnage well beyond its direct customers. Waiting for a bus in London? The ...

Most mobile phones rely on a small card called a SIM (subscriber identity module) to make phone calls and send text messages. Without it, your phone isn't able to connect with the cellular network and ...