Or you might need to enter an unlock code provided by your ... number—a unique identifier for every mobile phone manufactured—into an online tool on the carrier’s website.

Mobile phones aren't all that mobile when it comes to switching carriers—or even owners. It may seem like a no-brainer to accept a hand-me-down phone from a friend or family member or buy a used ...

If you buy through a BGR link, we may earn an affiliate commission, helping support our expert product labs. As anyone who has had the misfortune of walking into a dead zone can attest, not all ...

A "locked" phone can only be used with that carrier; it cannot be used with another carrier's service. (Not counting roaming.) This lock can usually be removed by entering a special code or ...

T-Mobile's appeal lies in its multiline discounts for families who want wireless coverage. Picking the best cell phone plans requires extensive research on exactly what each carrier offers.