Originally Posted by
Rukbat How do you tell? By the model number. G960W is an unlocked (by Samsung) Canadian phone. G960U is an unlocked US phone. G960P would be phone locked to Sprint. (But Sprint and Verizon don't usually SIM-lock their phones.) Anything else is probably unlocked by the carrier, but I can't see a carrier unlocking a phone.
Who updates it? Since it's not on the original carrier, probably Samsung. If it's the factory unlocked version (U or W), Samsung. So either way, probably Samsung.
As far as I know, Sprint does SIM lock their phones and it was announced in February that Verizon would start SIM locking their phones soon.