The subscriber identity module -- SIM -- contains the information used to connect to your wireless carrier's network from your iPhone 4. If you are planning to resell your company's iPhones, you ...

Once you’ve activated your iPhone with your carrier, it should continue to work on the cellular network without any problems as long as you’re within range of a tower. Nevertheless, the vagaries of ...

Most people manage perfectly well with a single SIM card, but some people like to have separation between their work and home life (or maybe they run several different businesses), or they travel a ...

If you need to find out your iPhone's carrier without a SIM card installed, you can do so through the Settings app. Usually the cellular carrier name will be displayed at the top of your iPhone, but ...