With the amount of competition between cell phone service providers, your phone may have a service lock to ensure customer loyalty. With a locked phone, any SIM card from another service provider will not work. In order to use your cell phone with another wireless provider, you must obtain an unlock code from your previous provider or a third-party unlock company.
Check your cell phone to make sure it is SIM-card compatible. Only phones that have a SIM-card slot and uses GSM technology can be unlocked and used with a provider of your choice. If you are using a cell phone that utilizes CDMA technology, it will not be able to take a SIM card. SIM card slots are generally hidden behind the battery of the phone so you will need to remove the back cover of your phone and take out the battery.
Call the previous service provider that distributed your cell phone and request a cell phone unlock code. If you've had your phone for three months and are current on your service agreement, you are entitled to a free service unlock on your phone. If you break your service agreement or have not had the phone for three months, you still can obtain an unlock code from a third-party unlock company. Since each cell phone has a different unlock process, your previous service provider or the third-party unlock company will give you specific instructions on how to access the unlock mode and enter your code.
Purchase an unlock code from a third-party company. You must first find your phone's unique IMEI number by entering * # 0 6 # into your phone and press the "Send" or "Call" button. A message will appear with a 15- to 17-digit IMEI code. Provide the IMEI number to the unlock company and it will send you an unlock code with step-by-step instructions on how to successfully unlock your cell phone.
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