iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 7 Plus (Global), released on 2018-04-24T17:11:29Z. The update package is 801.02 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 70022f420b5052265a6a6364a1a149c4f52cb7e5.zip.