iPhone upgrade

Taxes and fees will depend on your location.

Normally you would need to pay sales tax on the new iPhone as established by your country (and state and local government in the case of the U.S)

There should not be additional fees on top of that, if doing the upgrade through Apple's iPhone Upgrade Program.

If doing it through your carrier / mobile service provider, you would to need to ask them about any upgrade fees they may have.

iPhone Upgrade Program - Apple

Read about it in the link above. You would probably have to run your phone through the system since a lof of this will depend upon information only you know such as model phone and country where you live.

Yes, what I already said 15 minutes earlier about cost and other factors depending upon your location. ◔_◔