I have two plans on our account. One is good for an upgrade with discounts, but the second plan is the one I want a new phone on. Can I buy a new iPhone 7 on the first plan, and then swap it with the iPhone 5 on the second plan? I believe the two phones now use different SIM cards, so how can I make that happen so that I can take advantage of the discounts on the first account, and get the better phone onto the second account? Make sense?