iOS 9.3 (build 13E234) is an official Apple over-the-air update for the iPhone 6s+, released on 2016-03-21T18:56:38Z. The update package is 312.42 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bc53c6d8ec6304f93fbc29fe93d34e1333c4075a.zip.