Upgrade my 7+ iphone

Hello~ If you mean update …your iPhone 7 Plus can only be updated to iOS 15.8.3. If you are in need of a higher version of iOS you will need a newer iPhone. Click below to shop for a new device…

iPhone - Apple Official Site

If you purchase a second hand device please take a moment to read these helpful links by clicking on below to make an informed decision…

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Also:

The All Too Common SAD Reality of Buying a Used iPad/iPhone

~Katana-San~

You cannot update an iPhone 7 Plus to iOS 16 or higher.

If you purchase a new iPhone, I would recommend purchasing one that is compatible with iOS 18, and that also has support for 5G cellular bands. (Some of the earliest iPhones that can run iOS 18 are not 5G-compatible.)

If you want Apple Intelligence, you will need an iPhone 15 Pro, 15 Pro Max, or 16-series phone. (Those are the only ones with 8 GB of RAM, and the only ones that can get Apple Intelligence – if it is available in the part of the world where you live.)