SIM Unlock

A few GSM phones implement both locked phone and locked SIM security features. This is, of course, not so much to protect your information as to prevent you from switching providers. This is a pretty rare security measure. In some cases, a person purchases an unlocked phone from a third party (a company that does not have a deal with a provider) and upon inserting his or her old SIM, the phone gives an error message to the effect of "SIM locked." This is different from the locked phone phenomenon. This means that the SIM card manufacturer has locked the SIM for use with the phone it was packaged with. There are a few methods for performing a SIM unlock. Do-it-yourself software methods can be dangerous, as the incorrect password may render your phone unusable. The best idea is to simply call your cell phone service provider and ask for the SIM unlock code, which, in some cases, they are more than happy to provide!