Hi there, A generous friend let me use his upgrade to purchase a 6 today. When we receive it, can I pop my nano sim in and use it without activating it on his account, or do I need to do that first? I'd love to skip the step that involves his phone going offline as he is going out of town. If it does need to be active on his account, can I activate it on mine while he is gone and then temporarily put it on his later? Thanks!