Okay, so I'm in charge of the AT&T account for myself, my mom, and my sister. I have unlimited data, my sister 2GB, and my mom 300MB (she works from home, so rarely needs cellular over WiFi). I've been debating back and forth on NEXT, but I want to keep my unlimited and honestly, don't like NEXT pricing since my mom and sis need so little data. Can't I do the following? - I buy myself the iPhone 6S on Apple's payment plan - My sister buys herself the iPhone 6S on Apple's payment plan - Zero changes are made to the AT&T account - I activate my new 6S from my 6, and continue using my unlimited data - My sister activates her new 6S from her 5c, and continues using her 2GB of data - My mom continues to use her 5c and 300MB of data ... basically using the Apple subsidy to get the phones now, and pay them off over time. Basically, just using it as a "buy outright" option, but not having to drop $950 for each phone up front.