I just ordered an iPhone 7+ using the installment plan while also receiving an upgrade credit for my current phone. Next year, when the iPhone 8 (or whatever it will be called) becomes available, will I be able to trade-in my iPhone 7+ and purchase the new phone under the installment plan? I know you can do this with Apple directly, but it's unclear if the same model is applicable with Verizon. I haven't been able to find a definitive description of the plan details, either. If someone can point me to that document or web page I would greatly appreciate it.
As long as you've paid at least 50% of your installment on your iP7+ then you should be able to upgrade to whatever Apple decides to call it's next offering of the iPhone.