iOS 12.3 (build 16F5139e) is an official Apple over-the-air update for the iPhone 6s, released on 2019-04-22T17:08:59Z. The update package is 403.7 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: 0da79f31ce216fa8ad3e9e2472964277c9e98071.zip.