iOS 12.3 (build 16F5156a) is an official Apple over-the-air update for the iPhone 6, released on 2019-05-10T17:09:45Z. The update package is 403.89 MB. This is a delta (partial) update that requires 12.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1c19d3566181e06f842dc7563f9521985c8bb124.zip.