If you purchased your cell phone from a carrier such as T-Mobile or AT&T/Cingular, chances are that you bought a "locked" phone. A locked phone is only capable of working with one carrier. GSM cell phones can easily be unlocked, after which you can use the phone with any network's SIM card. Depending on the network the phone is locked to, there are ways to unlock the phone and remove SIM restrictions.
Instructions
1. Request your network carrier to provide you with an unlock code. Different carriers have different polices regarding phone unlocking; T-Mobile, for example, will give you the unlock code if you keep your account active for 40 days as a post-paid customer, or 60 days as a prepaid customer. When the carrier provides you with the code, follow its instructions to unlock it.
2. Purchase the unlock code from a phone unlock website. GSM cell phones can be unlocked using a code. To purchase the code, you need to provide the phone's IMEI number to companies such as GSM Liberty, Unlock All Cellular or Cell Corner. For some older Nokia phone models, you will be able to get free unlock codes from websites such as Nokiafree.org. Upon purchasing the code, you will get the instructions for entering the code.
3. Buy unlock software, if the unlock code doesn't work. Software unlocking involves unlocking the phone using a special cable. Each cell phone model will have different unlocking instructions. The unlocking software is generally sold by websites that sell unlock codes.
4. Take the phone to a cell phone repair center if you can't find the code or software. You might be charged $25 to $50, as of 2010, for unlocking at a retailer.
Tags: unlock code, cell phone, cell phones, have different, locked phone, phone locked