An increased number of reports coming from Sony Xperia Z owners all over Europe talk about Sony Mobile rolling Android 4.2.2 JellyBean software update to the handset.
The new firmware build number 10.3.A.0.423 is available for the Xperia Z C6603 (4G LTE) version in Europe as follows: Spain, Ukraine, Turkey, Austria, Czech Republic, Hungary, the Netherlands, and in Hong Kong (Asia). The same build is available in Taiwan too, but for Xperia Z C6602 (HSPA+) variant.
The upgrade might be available in other countries as well, but because it is rolling out in stages it will only be available to a limited number of users. If you manage to pull it in on to your Sony Xperia Z smartphone somewhere else, please do let us know in the comments down below.