iOS 8.3 (build 12F70) is an official Apple over-the-air update for the iPhone 6+, released on 2015-04-08T17:56:16Z. The update package is 579.65 MB. This is a delta (partial) update that requires 8.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 40bea2f16332af1af336d68f135a115749c34666.zip.