Paid for Sky iPhone upgraded for non-Sky iPhone; does my Sky account need to be updated?

[Poppet15]

My sky mobile iPhone has been paid for and I have upgraded to a new iPhone but not through Sky. Do I need to show my new phone model on Sky account?  It is still showing the original phone and I can't see anywhere to update/remove it. Since getting my new phone (as I say not from Sky) I have taken a sim only 12 month contract with Sky, and ported my number, however, I'm having issues with activating iMessage and FaceTime and not sure the different model of iPhone on Sky account is causing the problem?  Sky have sent out a replacement sim but issue still continues, even after 24 hours. 

[GD1]

@Poppet15  As the phone has been purchased elsewhere it won't and can't be added to your mobile account.