Regarding if a phone is genuine or not
Hello, so I want to buy an Xperia U, second hand, and it's from another city, but it would come by courier, with the possibility to check it. The thing is, how can I tell if it's genuine or not? Any particular things I should check? I read a while back, if I remember correctly, I have to dial a special number, or am I going off-rails haha? Please let me know for things I should check, thank you!