If you wanted an iPhone without necessarily being tied to a carrier, your options just expanded. Apple has started selling unlocked versions of the iPhone 7 and 7 Plus.
When Apple started selling its new iPhones in September, its website required you to pick one of the four major carriers when you bought an iPhone 7 or 7 Plus. Now there's a new option: you can buy a SIM-free iPhone that you can activate with any carrier later — or at least a carrier that uses the cellular bands supported by the iPhone. (Apple lists those bands on the specs page for the iPhone 7 and 7 Plus under Cellular and Wireless.)
By grabbing a SIM-free iPhone 7, you're not tying yourself to a specific carrier right out of the gate. However, you won't be able to pay off your phone in monthly installments; instead you'll have to pay the full amount when you buy your iPhone. The iPhone 7 starts at $649 while the 7 Plus has a $769 price tag for its base model.
SIM-free iPhones are available in all colors. You can order them online for now, though Apple will likely ofer unlocked phones at its retail stores as more inventory arrives.