1. On your BlackBerry, go to Setup >> Options >> Device >> Advanced System Settings >> SIM Card.
2. At that screen type MEPD (see note below) on your keyboard. A new menu will pop up and show you information similar to one our our devices:
SIM = Disabled
Network= Active
Subset = Disabled
Service Provider = Disabled
Corporate = Disabled
If your BlackBerry has a SureType keyboard (71xx and 81xx devices) you will need to double-tap the P, so the actual keys entered become M E P P D.
3. If your device is “unlocked”, Network should report either Disabled or Inactive. If it says Active, the device is still locked to that carrier.
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Another method to determine if your Blackberry is “unlocked” is shown below:
1. Power-off your Blackberry.
2. Remove the back cover and battery pack.
3. Carefully slide-out the T-Mobile SIM card and replace it with a SIM from another carrier.
4. Insert the battery pack and reinstall the cover,
5. Power-on your Blackberry.
6. If your device is locked to T-Mobile, you will receive the message
“The current SIM requires an Unlock Code. Enter the Network MEP Code.”
