Let’s say you spent your vacation abroad a couple of years ago. Being thrifty, you removed your U.S. SIM card from your unlocked iPhone 4 and inserted a SIM card from a carrier in the country you were ...

While most people seem to manage just fine with a single SIM card in their smartphone, some -- especially travelers, who can save money by fitting a local SIM card into their handset -- love the ...

The SIM cards that fit into those tiny slots in your cell phone and tell your cellular network to whom your calls are to be charged come in four different sizes. With the only real difference between ...

While most people manage quite well with a single SIM card, if you want better demarcation between your work and home life, or you want to make roaming with multiple SIM cards easier, then having the ...

If you’ve bought an iPad with 4G/cellular capabilities (we discuss whether that’s a good idea in our 2015 iPad buying guide) or a new iPhone, you need to buy and install a SIM card. Here, we explain ...

SIM cards have been an integral yet forgettable aspect of owning a smartphone over the past few decades. For most users, the SIM card defines the basic commercial relationship they have with their ...