Unlocked Global Systems for Mobility (GSM) phones are cellular telephones that are not locked to one wireless provider's network. In the United States, unlocked GSM phones can be used on T-Mobile and AT&T wireless networks.

Function

Cell phone providers lock their GSM phones to prevent them from being able to read any other wireless provider's Subscriber Identification Module (SIM) card. Conversely, unlocked phones have the ability to read any active SIM card inserted into the device.

Benefits

Unlocked GSM phones can be purchased from third-party sellers without having to sign or renew a cell phone contract. Also, the phones can transferred between wireless providers if users want to keep their phone when they switch providers.

Identification

GSM phones have a SIM card slot located underneath the battery door. An unlocked phone isn't physically branded by a wireless provider; however, once an active SIM card is inserted, the phone's electronic display will show the name of the wireless provider listed on the SIM card.

Geography

Unlocked GSM phones provide users with cheaper calling options while traveling abroad. Users can purchase a SIM card when they reach their destination, insert it in the phone and make calls at a greatly reduced price.

Potential

Unlocked GSM phones are legal in the United States and are worth a great deal of money on the open market. The phones are in great demand since they can be used on any GSM network in the world.

Source:

Ebay Guides Unlocked Cell Phones

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