OTA Updates/iPhone/9.x

Users still on iOS 5.1 through 7.0.6 must update to 8.4.1 via OTA prior to installing OTA updates for iOS 9.0 or newer. Exceptions to this are iOS 6.0 on the iPhone 5 and devices that were introduced with iOS 7 (iPhone 5c, iPhone 5s, iPad Air and iPad mini 2).

Users still on iOS 7.1 through 7.1.2 may update to iOS 9.0 or newer, but appear to be given a dummy update first.