Question : Problem: How to ensure newly  purchased iphone is factory unlocked

Recently I brought Iphone after shop keeper assured me it was factory unlocked.
How can myself check the same. if there any options available in the phone where I can check the same, if so, please give the detail navigation to view the information to ease while checking.  

Answer : Problem: How to ensure newly  purchased iphone is factory unlocked

Best and fastest way is to plug in your SIM card and see if you receive a signal.