Which size SIM do I need for my iPhone: SIM, Micro-SIM and Nano-SIM

You’ve just bought yourself an iPhone – welcome to the club! However, while you thought you’d just be able to pop your existing SIM card into your iPhone, you might be wrong. Here, we explain the differences between SIM, Micro-SIM and Nano-SIM, and explain which size SIM you’ll need for your iPhone.