A:Answerno, if you're their customer you can just call them and as long as you have the S/N from the sim and the IMEI number from your phone then they will take care of it for you within a few minutes
A:AnswerIt most definitely will because I just did it 3 days ago our plan was to go into the Best Buy and tell them I would like AT&T prepaid sim card activated. Well the lady helping me wanted my phone number wanted my name all my info on my account and I was like great now I'm going to have to pay for a SIM card and it probably won't even work. But it worked like a charm and I'm using it. My bill was nearly $200 and it's only me on my service crazy!! All because I wanted a Galaxy S 8 + but I still have it and still paying on it except not right now with the prepaid but I'm getting to use my Galaxy. I hope this helps you