iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2018-03-29T17:11:32Z. The update package is 751 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 09881318bddf9067f25b8c6bccd998b75ea912dd.zip.