Many wireless providers across the globe, including AT&T/Cingular, T-Mobile, Vodafone, and Verizon sell Blackberries.

When these companies sell a BlackBerry, they do so at a discount in order to attract customers. The providers then make up the lost profits over the lifetime of their contract with the customer.

To protect those profits, the wireless providers configure a “subsidy lock” into each BlackBerry. The subsidy lock prevents the BlackBerry from being used on another provider’s network.

BlackBerry Unlocking

There are four known methods for removing the subsidy code and unlocking the BlackBerry.

Call the Wireless Carrier

Many wireless carriers disclose the unlock code if certain requirements are met. These requirements normally include being a customer for a minimum amount of time and having the account paid up.

Most wireless providers do not charge for this service. Rogers is a significant exception, as they attempt to extort $250 from their customers for this service.

Calculating the Unlock Code from the IMEI

Most providers use unlock codes that are generated from the BlackBerry’s IMEI number.

Many small companies exist that have taken the time and effort to crack the algorithms used to generate those unlock codes.

These companies usually run websites where users can enter their IMEI number and receive an unlock code. They might do so for a fee.

However, this method does not work with BlackBerries from all wireless providers. Some wireless carriers assign the unlock codes to each phone randomly and store the results in a database. There is no way to algorithmically determine the unlock code for a BlackBerry from one of those providers.

BlackBerry Unlocking Software

Specialized software that erase the subsidy locking code from GSM BlackBerry phones exist.

Users can install this software on their PC and plug the BlackBerry into its docking cradle or into a USB sync cable.

BlackBerry Unlocking Hardware

If all else fails, there is specialized hardware that forces a BlackBerry to forget its unlock code.

This hardware usually takes the form of a clip or a box. Plug this device into the BlackBerry and it erases the subsidy lock.

However, it is less expensive to either take the phone into a local shop or send it off to a specialist company than to purchase this device.

How to Unlock a Blackberry with the Code

Each BlackBerry has a unique Unlock Code. The code from one device cannot be used for another.

Once the Unlock Code is obtained, unlock the phone by following the instructions given or the following steps:

1. Go to the Settings Menu -> Options ->  Advanced Options -> SIM Card

(Please Note: There might be different ways to reach the “SIM Card” option for some of the phones)

Once the “SIM Card” option has been selected, follow the steps below:

(N.B.: Entering the wrong Unlock Code more than 5 times will permanently lock the device to the original carrier. Be careful while entering numbers, since the ALT key must be pressed to do so)

Blackberry 8800/8300 Curve:

2. Type MEPD (NOTE: No text will appear on the screen while typing)

3. Type MEP2 (Remember to use the ALT Key)

4. The user will be asked for the  Network MEP Code. Enter the unlock code and press Enter.

5. The phone is now unlocked.

Blackberry 8100:

2. Type MEPPD (NOTE: No text will appear on the screen while typing)

3. Type MEPP2 (Remember to use the ALT Key)

4. Enter the Unlock Code and press Enter

5. Reboot the phone and it is now unlocked.

Blackberry 8700:

2. Type MEPD (NOTE: No text will appear on the screen while typing)

3. Hold down the ALT Key while typing in MEPE

4. The user will be asked for the Network MEP Code. Enter the unlock code and press Enter.

5. The phone is now unlocked.

BlackBerry 6xxx 7xxx:

2. Type MEPD for all models except Blackberry 7100 in which case use MEPPD.

3. Type MEP2 (MEPP2 for the 7100) (Remember to use the ALT Key)

4. Enter the Unlock Code and press Enter

5. The phone is now unlocked.