i called and if u have a nextel, sprint, or boost phone all these carriers work together so u can use a nextel phone for either sprint or boost and u can use a sprint phone for nextel or boost same with boost i have a nextel phone and iam useing it with boost...and it doesnt matter if it take sim card or not just save ur sim card just if u want a new phone and it takes one... and if it dont take a sim card u just call u phone company and they will switch all ur info to the new phone;