Audio Merger Software Free Download. I've heard complaints from the savviest of techies that even though their U.S. Cell phones now work with networks in the U.K., the rest of Europe and Asia, they're getting burned with some serious roaming and usage charges. Many have heard that they can switch out their phone's SIM card--the Subscriber Identity Module, or tiny smart card that identifies a phone and its subscriber--for a local one, but they weren't sure what this entailed. A phone that would work on foreign mobile networks and an impending trip to the U.K. Made it an ideal time for me to give it a try. Can Metro Unlock My Iphone there. Here's what I found: Using an alternative SIM card for your phone while traveling can be cheap and easy, but there are some tricky negotiations along the way. Step 1: Getting the mysterious unlock code Persuading your phone network carrier to give you the unlock code to your cell phone may be the most difficult part of the entire process.