Got this from MSE.........not sure any one got this
You can get free unlock code from T mobile.
All you need to do it write to them as the following address:
6 Camberwell Way
Doxford Technology Park
Tyne and Wear
Include your Handset make & model (eg. Nokia 6120 Classic)
Your unique IMEI number (press *#06# on your phone to get this)
Also include a contact telephone number and your name & address (or alternatively, your email address).
Hopefully that should save some of you some searching & more importantly, money!!
Thanks to 'tangovictor'