Last year my Verizon iPhone 6 Plus worked on both Verizon as well as AT&T. This year the unlocked phones Apple's selling have different model numbers: iPhone 6s Model A1633, iPhone 6s Plus, Model A1634 for AT&T etc., and for Sprint, T-Mobile and Verizon, iPhone 6s, Model A1688, iPhone 6s Plus, Model A1687. Their previous years Verizon would work on all, but the Apple unlocked wouldn't work on Verizon or Sprint. Not sure what the unlocked this year are going to be capable of, since unlocked model numbers require a carrier to determine which phone you're getting.