I was a Verizon customer and was transferred overseas for work. I had Verizon unlock my phone before I traveled and then about a month after I moved my contract with Verizon ended. I have had no problems using the local overseas sim card. My question is, when I return to the States for vacation or holidays, are there any options for any sort of pre-paid SIM cards that will work in this phone. It doesn't appear that Verizon offers them and from what I have read on these forums, a T-mobile or AT&T Sim card won't work, even though my phone is unlocked and out of the contract. Is that correct? Has anyone had any success with another US sim card? Thanks!!
The Verizon iphone 4S can be unlocked for overseas use on GSM networks, but it won't work on GSM carriers in the USA. You can certainly activate it on one of Verizon's prepaid smartphone plans while you are back in the USA. You will have to remember to cancel it when you leave again.