If you completed the carrier activation steps for AT&T, Sprint, or Verizon when you purchased your new iPhone online, it will arrive ready to use. Just turn it on and follow the onscreen instructions to set it up. If you chose to skip carrier activation at the time of purchase, you’ll need to insert an active SIM card or contact a carrier to set up an account. If you selected an iPhone for T-Mobile, it will come with the appropriate nano-SIM, but you’ll need to contact T-Mobile or visit an Apple Store to activate your iPhone. Apple Iphone 5 Unlocked Buy Online Usa. Buy Unlocked Mobile Phones In India. If you selected the SIM-free iPhone, you’ll need to insert your own nano-SIM card or obtain one from the supported carrier of your choice and activate it in order to use your iPhone. How Do You Unlock A Verizon Iphone 5c.