Upgrade sim only to contract phone

[Camp1828]

I ended my 3 year contract with sky and continued on as sim only. 
I now want to upgrade my phone, and keep the same number. However, the sim contracts are a lot cheaper than what I already pay as a sim only.. is there a way I can get the good deal without switching numbers and having to port the number to a PAYG sim and back again as I don't know how this would work?

[caesarome]

If you finished paying your phone off then you will be unable to upgrade it as you would have to take a new contract on a new device instead.

Regarding the sims all you could do is to call Sky when you are ready to pace the order to ask them if they would apply the sim deal into yur current sim. If they will not do this then you will have to take out another new sim and port the number on your current one to a PAYG sim then back to the new one.