As it has for previous iPhone models, Apple is now offering a sim-free version of the new iPhone 7 and iPhone 7 Plus. For the first few weeks since the new iPhones were announced, only units tied to specific carriers were available.
With an unlocked phone, it's your responsibility to contact a wireless carrier such as AT&T or Verizon, secure service and activate your phone. Phones ordered tied to a specific carrier typically arrived already linked to your phone number and ready to activate and use. The sim-free phones support both GSM and CDMA networks, so they're compatible with any of the major carriers.
While ordering through a carrier often gives you the option of getting a phone through a leasing or monthly payments option, Apple offers sim-free buyers an 18-month payment plan if they don't want to pay the full price, starting at $769, up front.