what is a sp code on a mobile phone?

i have unblocked a mobile phone but when i turn on the phone it asks for a sp code. can anyone help.

SP code is also known as Service Provider code . I think your phone is locked with your present carrier . To unlock it, use unlock code . If your phone is Blackberry, get unlock code from UnBBLock.com . If your phone is other than Blackberry, get unlock code from SimpleUnlocking.com .