Q. What does it mean for a mobile phone to be “locked” in regards to international travel? Does that mean it will not work overseas?
A. In this situation, a “locked” phone works only on the network of the wireless carrier that activated the device and not on the network of a competing domestic company. Locked phones can “roam” onto international networks, but without the proper service plan from your carrier, the charges for international roaming can be hefty.
“Unlocked” devices are free to use other networks around the world. Travelers who want to buy a local number and an inexpensive data plan can then swap in a compatible SIM card (short for subscriber identity module) from international wireless carriers.
If your phone meets certain requirements, you can ask your carrier to unlock it from the network. Those requirements vary by company, so check with yours before you go.
Verizon doesn’t lock most of its phones (except for some in its 3G World Devices line). If you’re an AT&T, a T-Mobile or a Sprint customer, or use another carrier, check the company’s site for unlocking instructions. In most cases, typical requirements include a completed contract commitment with the company and a device that has not been reported as lost or stolen. Many requirements are waived for active-duty members of the military.
Most carriers will also have instructions for changing out SIM cards from your phone model. You can also find the information on the site of the phone manufacturer, like Apple, Google or Samsung. When exchanging SIM cards, make sure you get a new one in the correct size for your phone and keep the old one in a safe place.
If you are traveling abroad just for a quick trip and do not want to fuss with unlocking the phone or juggling SIM cards, ask your carrier about getting a short-term international plan for voice and data. Investing in an inexpensive “burner” phone and a local SIM card is another option that may cost less.
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