iOS 9.9.12.3 (build 16F156) is an official Apple over-the-air update for the iPhone 6s, released on 2019-05-13T17:08:03Z. The update package is 2.2 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: 29eaed39056ef020ea6185428fd7d2bdb590f233.zip.