A sim card is a sim card. Once that is activated as a post-paid, it's a post-paid and can't be changed. In fact if you de-activate it, the sim card is unusable and must be replaced. You can get them on ebay for about $5 but verizon needs more...maturity with sim cards. ATT has a decent policy, you go into a store and simply ask for a sim card and they hand you one, no questions asked. At this point, the last I heard, verizon can't even sell you a sim card. They definitely have some learning to do.