I am on my 3rd 4s. My first one was shipped direct by Sprint and when I switched phones at Apple they gave me the sim to take to the Sprint store to activate the new phone. The Sprint store employees were confised by the whole process, and even denied that there was such a thing as a Sprint sim for the iPhone! Anyway, I showed them then sprint details on it and they agredd it was a sim, called apple themselved and figured out how to get the sim in the phone - that was my second iphone. After a lot of problems with that phone I got a third and final one and it was activated in the Apple store, no going in to Sprint. Yesterday, I opened the sim card slot and it is empty! I will be travelling in a few days to France, Israel and Italy and need to be able to use my phone in all thosie countries. Do in need the Sprint sim? To point out, the phone was activated after Sprint said they will be locking the sims, and also my company will pay roaming so I would only use the Sprint roaming anyway, please advise! I did call Sprint, the customer service rep I spoke to had no understanding of what I was asking and said that roaming internationally on sprint didnt require a sim, when I asked why there was a sprint sim my question was ignored. Not such a happy sprint customer!