Sony declared late last year that the Xperia Z1 and Xperia Z Ultra would be updated to Android 4.4, and starting today the company is making good on its promise.

Sony has announced that it's begun to push Android 4.4 updates to the Xperia Z1, Xperia Z1 Compact and Xperia Z Ultra. In addition to the bump up to the newest version of Android, the updates include some user interface tweaks, updated versions of Sony apps and Xperia Themes, a feature that allows users to quickly and easily skin up to 280 pieces of their handset's UI. The full rundown of goodies included with the KitKat update is as follows:

• Google’s Android 4.4; KitKat as standard – bringing performance & UI optimisation
• We’ve added our tweaked Status Bar and Quick Settings… now more intuitive and customisable (and pretty easy on the eye)… cleaned up to ensure you only get the notifications you really need
• If you’ve got a Sony PlayStation 4, you might recognize our new user interface – we’ve added the same sleek launch animation and live wallpaper across the lock and home screens
• We’re also uplifting Sony’s entire native app portfolio to the latest versions – bringing tweaked / improved / current experiences for (to name but a few): Messaging, MyXperia, Smart Connect, Small apps, TrackID, TrackID TV, Sony Select, Smart Social Camera and…
• Sony’s Media apps: WALKMAN, Album and Movies, with Sony Entertainment Network cloud service integration* – a more converged and full Sony entertainment experience – Sony Entertainment Network & PlayMemories integration with a more intuitive UI, better download speeds, and more!
• Our unique custom interface experience: “Xperia Themes”, with downloadable UI packs from Sony Select – skin up to 280 assets across your Xperia smartphone with a variety of styles, and more to follow soon…

As is the case with most software updates, exact availability of this bundle of new software will vary by market and carrier. It's nice to see that the push has officially gotten underway, though, and the update to KitKat may help owners of the Xperia Z1 forget that their handset is no longer the top dog of Sony's Android lineup.

Sony today also confirmed its plans to push Android 4.4 updates to several other Xperia smartphones. The company says that KitKat will be made available to the Xperia Z, Xperia ZL, Xperia Tablet Z and Xperia ZR starting in the middle of the second quarter. The Xperia T2 Ultra, Xperia E1 and Xperia M2 will be bumped up to Android 4.4 as well, but the timing of those updates aren't yet known.

Via Sony