Phone Unlocking have been asked to see if any one knows

[mapman]

have been asked to see if any one knows my m8 has a 3g phone a sammi can he get a simm to replace this ,ie o2 or other sim it was a contract phone is locked but i am willing to find code to do this .
so his phone is 3g can it be changed to any othere network without unlocking

 

[Blartiartfast]

If you are trying to say "If I unlock this phone, will it work on other networks"....then yes you can.
If it was on contract and the bill hasn't been paid then no.