How can I update my iPhone 7 when iOS 16 is not available?

You cannot update your iPhone 7 to iOS 16 or later.

The iPhone 7 ran iOS 10 when Apple introduced it in September 2016, over eight years ago. It got five iOS updates, but is now at the end of the line.

I'd suggest buying an iPhone that is compatible with iOS 18 – preferably a recent one. (The very oldest iPhones that can run iOS 18 might be at, or close to, the ends of their lines.)

An iPhone 7 cannot update past iOS 15. If you need a newer iOS version, you will need to get a new phone.

iOS 16 is certainly available, but you will need an iPhone 8, iPhone 8 Plus or iPhone X to run it. The iPhone 7 can't.

However, because the current iOS version is iOS 18, it would make sense to look for an iPhone that can run iOS 18. I would recommend an iPhone 15 or iPhone 16 version, so you will be able to run new iOS versions for the next 5 years or so.