Can I upgrade from iPhone 4S to iPhone 5?

I got the iPhone 4S for christmas 2011, on a 2 year contract for £25/month with EE. At the end of my contract I can get a free upgrade and I was wandering, as it will be the end of my contract around the end of this year/beginning of 2014, would I be able to upgrade to the iPhone 5?
Any websites to see what other phones I could be able to upgrade to are also what I'm searching for.

No

you have to get a new phone

you can probably arrange a trade… To give your 4S and pay additional to get the 5

You can upgrade softwares from iPhone 4S to iPhone 5 like operating system of iPhone 4S i.e. IOS 5 which is Up-gradable to iOS 6.1.3 and you can take advantages of new software applications as an iPhone 5. But you can't upgrade its hardware as an iPhone 5.