When I buy from the Apple Online Store, does my iPhone come ready to use?
Yes, if you have selected an iPhone for use on AT&T, Sprint, or Verizon. When your iPhone arrives, all you have to do is turn it on and follow the onscreen instructions to set it up. If you have selected an iPhone for T-Mobile, it will come with the appropriate nano-SIM, but you will need to contact T-Mobile or visit an Apple Retail Store to activate your iPhone. If you have selected an unlocked GSM phone, you can insert your own nano-SIM card or obtain one from the supported GSM carrier of your choice and activate it in order to use your iPhone.