iOS 12.3 (build 16F5156a) is an official Apple over-the-air update for the iPhone 6s, released on 2019-05-10T17:09:48Z. The update package is 404.74 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: 64b019c0dfc5abf5db233e5c28029e9b870d6e97.zip.