iOS 8.1.3 (build 12B466) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2015-01-27T17:55:06Z. The update package is 260.87 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: 9c775c99ce0d183b74457af499912aab129ad326.zip.