Today, we have some bad news for people who purchased the Sony Xperia T, Xperia V, and the Xperia TX. These devices won’t be officially receiving KitKat Updates and will stay on Jellybean 4.3.
Sony evaluated many of its older devices to judge whether or not an Android KitKat would be feasible and ideal for them; unfortunately, it seems not for these three devices.
On their product pages it now says that their current version (4.3) is the latest and final official Android update they will receive.
If you own one of these devices don’t lose hope. The developer community almost never disappoints, and it is no secret you will be able to install unofficial KitKat builds from forums like XDA.