Hi, i own a blackberry 9520, it was from O2 so it should be unlocked.

I have tested the handset with Vodafone and Giffgaff sim cards and it works no problem at all. When i try use an Orange sim card i get the message 'Your current sim card requires an unlock code would you like to unlock it'.

I am clueless to why this is appearing because it seems to work with most other networks. Can someone please advise me whats causing this and hopefully a fix to the problem.

Many thanks.

Could be a SIM with problem or it's just what the message says and you have to add a network unlock code for this SIM.

Hi, thanks for reply, in the end i just contacted O2 and yes i did need to get an unlock code from them for this particular sim.