A:Answer The Apple Watch Series 3 (Cellular) does not have a removable SIM card. While it is technically unlocked yes, carriers have to offer support for the cellular option. Here is a list of U.S. carriers that support the Apple Watch Series 3 (Cellular): AT&T, US Cellular, Verizon, Sprint, T Mobile and C Spire. To see more information on this product, please follow this link: https://www.apple.com/watch/cellular/