What is an Unlocked GSM Phone?

Some mobile network providers 'lock' their GSM cell phones, meaning that their phones have been programmed to only work with SIM cards issued by their company. Unlocked GSM phones don’t have this electronic restriction that prevents you from using SIMs from other wireless services.

In theory, just as any SIM card can be placed in any modern GSM phone, the opposite is also true. Any GSM cell phone can work with any SIM. So if you decide to change from one GSM wireless company to another, you simply keep your phone and replace the first company's SIM card with one from your new service provider.

Unlocked GSM phones work the same way as a normal GSM phone. A key advantage of unlocked GSM phones is that a subscriber can use his/her prepaid cell phone anywhere in the world without incurring expensive roaming charges, as they are able to support any GSM network in the world.

If ever you plan to use your GSM cell phone overseas, using a local SIM card gives you access to the local wireless service, which tends to save money and eliminate roaming and long distance charges. SIM cards can be purchased online for a number of international destinations.

The website TravelerInsider.info has a long and very informative FAQ on unlocking GSM phones.