iOS 12.3 (build 16F5148a) is an official Apple over-the-air update for the iPhone 6s, released on 2019-04-29T17:36:12Z. The update package is 404.78 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: c69a42c0c880dc689c28146461922989e7fa1f36.zip.