iOS 9.3 (build 13E5225a) is an official Apple over-the-air update for the iPhone 6s+, released on 2016-03-01T18:13:51Z. The update package is 1.67 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 54c0f614931871cacd8aa9bbe5d7e845cf19a1fa.zip.