T-Mobile SIM Card Activation Kit (T-Mobile) Compatible with T-Mobile&#39;s Nationwide 4G Network, as well as any other GSM carrier that uses SIM cards (like AT&amp;T). Compatible with any phone that uses a Mini SIM. Not compatible with phones that use a Nano SIM (like iPhone 5/5s, or 6/6 Plus ) Service Activation Card included Simply pop it into your unlocked GSM phone (phone that uses a SIM card) and you&#39;re all set!