How can I update an iPhone 7 Plus to iOS 16.0

How can I update an iPhone 7 Plus to iOS 16

You can't. The iPhone 7 does not have the "horsepower" to run iOS 16.

You will need an iPhone 8 to run iOS 16.

But, as long as you are looking for a new phone, it would make sense to make sure that it will run the current iOS 17 and future iOS 18. That would mean an iPhone XR or higher model.

Sorry, but you can’t. An iPhone 7 Plus cannot update past iOS 15.

Bob Timmons wrote:

But, as long as you are looking for a new phone, it would make sense to make sure that it will run the current iOS 17. That would mean an iPhone XR or higher model.

I'd suggest one that will be compatible with iOS 18 – though the two compatibility lists appear to be the same.

iOS 18 Preview - Apple

iPhone models compatible with iOS 17 - Apple Support

Unfortunately, the iPhone 7 Plus is not compatible with iOS 16 or higher.