I currently have an iphone 14 pro max that is 50% paid off but has monthly promotional credits. I am looking to add a line for my son and get the iphone 16 pro max with promotional monthly credits. Once I receive the phone and activate it, can I swap phone numbers between the two devices and keep the promotional credits on my bill so that my monthly payments stay the same or do I lose the promotional credits for both devices and end up paying full price for both phones?
