That's the hit. So if you trade in before the 2 years, you basically trade it in and get the rest of your iUP loan cancelled. So I had about $3xx left of payments on my iPhone 6s+. That gets cancelled soon as I mail back my 6s+ to Apple (they send a pre-paid mailer with my 8+), and I start my new iUP as soon as I get my 8+ in the mail (next week).
You're basically leasing the phone if you upgrade early. Which, some people like. Also, Apple emails you a SUPER EASY upgrade form to fill out online if you want (you can reserve phones in the store too if you prefer) under the iUP plan. Or, if you choose, keep the phone 2 years and it is 100% yours and you can sell it back.
By me upgrading early, I don't have to pay the $3xx I still owe on my 6s+ --- but I also get $0 for the phone. BUT, I also upgraded to the 8+ for only the cost of $45.xx + tax ($70.xx (California)) = $119. Instead of a $1100 kick in the bank, it is a 0% interest loan over the course of 2 years.
I am really happy with iUP so far. My goal is to keep my phone for 2 years so I can sell it but the temptation of upgrading to the iPhone 8+ for $119 was..... too much
.