iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone X (Global), released on 2019-01-22T18:08:50Z. The update package is 486.09 MB. This is a delta (partial) update that requires 12.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c8fc0fa43debca713f205d74ccabc82c2ee6d40d.zip.