iOS 8.3 (build 12F70) is an official Apple over-the-air update for the iPhone 5c (GSM), released on 2015-04-08T17:56:13Z. The update package is 388.75 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 24d14c366275f1c5351ad13eefa7ef175b50d60d.zip.