How to get unlock code

I have a T-Mobile blackberry pearl 8100 charcoal. I want to unlock the sim card and use it with some other carriers. Any help, please.

Thanks,

K

You don't unlock a sim card. You unlock a phone. There are 2 types of cell phone technology: CDMA and GSM. Verizon and Nextel are CDMA. T-Mobile(your type) and AT&T are GSM. If you have Verizon or Nextel you have to use a phone for that company. If you have T-Mobile and want to use an AT&T phone, you will need to unlock that phone. To unlock a phone enter *#06# and push enter. An IMEI number should appear on the screen. Write down that number. Make sure you don't mess it up. Then you need to buy an unlock code. Unlock codes are not free. Prices vary from a few dollars to $60 depending on the model of the phone and how much the person charges. I usually buy mine on ebay. Search for "unlock (model of the phone) (carrier)". Read the feedback of the seller and pick one with a good reputation that doesn't overcharge. Buy it and then email the seller the EMIE number. The seller should send you the unlock code and instructions to unlock your particular model. Please note that this does not work for the iPhone. Unlocking one of those is a whole different story.

and your type is T-Mobile.