Going back to iPhone
After 9 years of iPhone in November 2017 I upgraded to a Samsung S8.
10 months on, I just can't do it anymore and need to go back to iPhone.
I owe 22 installments of $25, so $550 on the S8.
Can I simply purchase an iPhone, go to ATT store, purchase and register a new sim and off we go?
I will want to sell the Samsung S8 so that I can apply the proceeds to the $550 that I still owe, will I or the buyer encounter any issues? Will I need to have it unlocked?