Unlock Almost Any Mobile Phone
Difficulty: Easy; Time: 20 minutes
If you travel internationally, you can save money by buying a local, prepaid SIM card and swapping it into your phone, instead of paying high roaming rates to your US cellular provider. Most US phones, however, are locked to a single carrier and function only with SIM cards from that company. Here's how to unlock your mobile handset for use on any GSM network.
First try to find a free code online that might unlock the phone. You can visit unlockitfree.com or bilemo.com/unlck, or you can begin by searching for your phone model online, using terms such as "Nokia 6820b free unlock code."
You'll be prompted on such sites to enter the phone's unique IMEI number (usually found under the battery), the model, and your carrier. With that data, the site will generate several codes and instructions for typing them into the handset. I recommend trying the first code returned at a few sites (since they can generate different results), instead of running though a full list of codes at one site.
If you're unsuccessful, try following the same process at a for-pay site, such as mobilecodez.com.