iOS 8.1.3 (build 12B466) is an official Apple over-the-air update for the iPhone 6, released on 2015-01-27T17:55:06Z. The update package is 261.4 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 45c0fcf24b056dd0fd2308d4ac3e697a09187187.zip.