Upgrade device but keep existing sky monthly tariff

[sj007]

Hi. Is it possible to upgrade my iPhone but keep my existing 10GB a month Sky price? There is a 'device only' option but not sure if that means NO sky monthly tariff at all and use another provider.  I don't want to select device only and lose what I have! 
I have a feeling that if I get a new device and want a sky monthly tariff, I'll need to pick a new one which is obviously more that what I am currently paying. 
tia

[caesarome]

The device and the sim are separate so you should be able to upgrade your phone only by selecting either the no sim or keep my sim option. If you do end up with a new sim (your new device might come with one by default) then do not activate t so it will be cancelled and you can continue using the one you have already got.