Learn how to check the software version and see official versions for the Sony Xperia Z3.
Beginning June 3, the Sony Xperia Z3 will have a mandatory software update to Android version 5.0.2/ Build 23.1.C.0.385 available via OTA push or Sony PC Companion over Wi-Fi only. This update provides features and improvements:

New Features Android 5.0 Lollipop Band 12 support

Improvements VoLTE improvements Device stability

Software version
Software update: Automatic (OTA)
Software update: Download

Check the software version

To check the current software version, follow these steps:

1. From the Home screen, tap the Applications icon.
2. Scroll and tap Settings.
3. Scroll and tap About phone.
4. Read the Build number on the phone, and check it below:

Build number	Status
23.1.C.0.385	Your software is up to date. There are no updates available. This document will be updated if and when new software is available.
23.0.D.1.123	Your phone can update to software version 23.1.C.0.385: Review the Requirements to update Starting June 3-TBD, you may be prompted to update automatically (OTA). To update now, see how to download the update below. If the update fails, see: Software update troubleshooting.
Other versions	Your phone has non-T-Mobile software, and it is unsupported. The manufacturer and T-Mobile cannot update your software.

Requirements to update

To be able to update to the current software version, the below requirements must be met:

• Build 23.0.D.1.123
• Wi-Fi connection
• 50% or higher battery life
• Available memory (File size is 636.6 MB)

Update automatically Over-The-Air (OTA)

To check for updates and download the update from the Sony servers, follow these steps:

1. From the Home screen, tap the All apps key.
2. Scroll and tap Update center.
3. Tap the System tab.
4. Tap on the available update, then tap .

Download and install software update

Update software from the phone
To check for updates and download the update from the Sony servers, follow these steps:

1. From the Home screen, tap the All apps key.
2. Scroll and tap Update center.
3. Tap the System tab.
4. Tap on the available update, then tap .

Update software from a computer
    To download updates for your phone and install them using a computer, follow these steps:

1. Install the PC Companion application on the computer you are using, if it is not already installed.
2. Connect your device to the computer using a USB cable.
3. Computer: Launch the PC Companion application. After a few moments, PC Companion detects your device and searches for new software for it.
4. Device: When notifications appear in the status bar, follow the on-screen instructions to carry out the relevant software updates.

Manually download and install software update

1. From your Home screen, tap the All apps key.
2. Find and tap Update Center.
3. Select the desired application or system update and tap , or tap to download all application updates.

Sources https://support.t-mobile.com/docs/DOC-16699