I bought a SGS5 (900F model) from Germany and although the box doesn't have a sticker saying its region locked to Europe I am assuming that it is region locked. Some websites say that apart from making 5 mins worth of calls with a regional SIM card it is also necessary to ensure that a regional SIM is inserted before the phone is switched on for the very first time in order to unlock the phone. Anyone knows if this is true? Do the 5 mins have to be outgoing calls or can they be incoming?