A locked GSM phone is one that the carrier who originally supplied the phone has "locked" so that it will only work with their SIM card. They do this to protect their investment. The prices at which the carriers sell these phones at is usually at or below their cost and they are expecting the recoup their subsidized loss by cashing in on the monthly voice and data plan costs over the life of the contract.

To you the consumer, I hate to say it but, this is really a fair practice. To many of us however, it makes us very unhappy. What if you fulfill your contract and want to move to a new carrier or you might be a world traveler who wants to buy a pre-paid SIM card in the host country to avoid international roaming charges. With many types of phones this can be a very costly and difficult process to unlock your phone. With just about every SmartPhone or PocketPC Phone Edition device, luckily, this is not that hard to do.


The manufacturer of the phone has a secret code that you can enter its different for each phone which will turn off the SIM lock. This will let you insert, say, a T-Mobile SIM in an AT&T phone. The carriers however are not so friendly when you ask for this code. Usually they will refer you to the manufacturer who will in turn refer you to the carrier. A vicious cycle.

How can you unlock your phone if you don't know somebody who knows somebody? You need to shell out some $$$ and "Git-R-Dun". There are many commercially available service to unlock your GSM phone. What these folks is a bit mysterious. Either they either have a line into the master unlocking code server for the manufacturer, or in some cases, they are just really smart and they have written software that decodes your IMEI number to divine the code. Often this involves running an application on your desktop/notebook with your phone in a special bootloader mode that unlocks the phone permanently. In almost all cases, this unlocking is permanent and does not have to be re-done when if you hard reset your phone.


There are many vendors who sell these SIM unlocking codes. A good example is IMEI-Check http://www.imei-check.co.uk/. Just about every one of our editors/moderators and piles of our users have used this service and they are first class. Codes are instantaneous and always right on.