If you've just got your hands on a shiny new Sim card, congratulations. Switching your Sim (the chip that dictates your allowance) can unlock huge savings. Now comes the crucial step of activating it ...

We previously reported that a tiny handful of iPhones shipped without SIM cards, while significantly more units have generated the error message "No SIM card ...

Sareena was a senior editor for CNET covering the mobile beat, including device reviews. She is a seasoned multimedia journalist with more than a decade's worth of experience producing stories for ...

O2 is one of the leading telecom brands in the U.K., providing mobile SIM card and broadband services. As a customer, it allows you to customize your monthly plan according to your needs. If you have ...