How much will I have left to pay off my iphone 5?

I have had my iphone 5 since October I think, I'm wanting to get the iphone 5s so I'm thinking about selling my iphone 5 then paying what I owe off then getting the iphone 5s, but I'm wondering how much i'll have left to pay off? I bought the phone for £160 and I pay £37 + £5 insurance, it's a 64gb iphone I have, can anyone help!

Every cell phone carrier has different upgrade fees and rules. Call your wireless carrier.

Usually they just take the amount of months you have left and multiply that by your monthly payment, so let's say you have 13 months left, that means you still owe £546, some networks will also add a cancellation fee but others will simply require you to pay off the remaining amount on your contract.

Call them and ask them, once you have paid off the contract obviously your current phone is yours to do as you please with so you have to then decide if you can make the money back by selling it.