hi to purchase codes visit http://www.prounlocking.com/ here they ask you the country and the network name to which your mobile is locked then the imei number of your samsung sgh-d900 mobile .finally they send you codes to unlock your mobile.
fairy12
April 2012
Here is a website that will answer your question. Only attempt to unlock your phone yourself if you are sure you know what you are doing! http://gleez.com/articles/did-you-know/samsung-secret-codes
howtomendit.com for free repair help, information and advice.
