Can I upgrade from a iphone 4s to a iphone 6?

AT&T, And My upgrade is coming up really soon so? Is the upgrade free if I upgrade to a iphone6?

Of course it's not free. Ask AT&T.

The upgrade is not free but if you sync with iTunes, all of your apps and data will carry over

If your CONTRACT is up, then you get the best deal. AT and others tell you that you*qualify for an upgrade* - which is the way they say - "You are lusting after a new phone, and YES! - we will gladly take MORE MONEY form you! Get some good PERSONAL advice from a really smart friend-or write back here with All the details. Do NOT listen to the people at ATT - they are there to UPSELL you!

IPhone 6 will cost you $99 when upgrading, it's not free.

Yes you can but, you have to pay fee for upgrade. But that's good deal. To give excellent security to Your Smart Phone, do install Leo Privacy Guard, user interface, simple, handy and intuitive.