Originally Posted by timshau

I have found both Cingular and T-Mobile willing to unlock the SIM as long as you have had the phone for a while. The reason I gave, truthfuly, is that I travel internationally and want to use a pre-paid SIM with a local number rather than pay expensive international roaming rates. There is a unique unlock code for each phone based on the IMEI number. T-Mobile says they get this code from the manufacturer once requested by the customer.

Below are the instructions from T-Mobile for the 7100 - just so everyone knows what the process is. Note that you only get 10 attempts to unlock before the SIM is permanently locked, so be careful - stop before step 5 unless you have an unlock code.

This posting does not include the unlock code - you will have to contact your carrier for this and they will send you the information or help you do this over the air. Note that both Cingular and T-mobile wanted to do this from a land line with your mobile available.

You can follow steps 1-4 without any danger to find out if your SIM is locked or not. If unlocked for T-Mobile, the Network is "inactive" rather than "active" in step 4.

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Thank you for taking the time to contact T-Mobile. Below you will see the Instructions for unlocking your Blackberry 7000 Series.

NOTE: If you receive an error message while performing the instructions below, stop. Please be aware that if an excessive amount of incorrect attempts are made, the phone will be permanently locked. Verify the IMEI by pressing *#06# and submit a new request. You have 10 attempts to enter the correct code.

To Unlock:
1. On the Home screen, click the Tools icon. The Options screen appears.

2. In the tools screen, select the Settings icon.

3. Scroll to SIM Card and select it. You should see the phone number and the SIM ID number.

4. Type 'mepd' to display the first five levels of SIM locking. T-Mobile uses network locking so the Network should display Active. All other states should display Disabled

Please note: For the Blackberry 7100t you will hit the "P" twice when entering the 'mepd' and 'mep2' for steps 4 & 5.

5. Type 'mep2' to display the dialog box asking for the unlock code (Press the Alt + 2 key to get the number 2)

6. Input the SIM Unlock code (it will be 16 digits long)

7. Press ENTER and reboot handheld.