If the recent PTCRB certifications of Android 5.0 Lollipop on the Xperia Z3 weren’t enough of a clue that T-Mobile was testing the firmware, then you can now hear the information directly from the horse’s mouth.
T-Mobile’s software updates page lists both the Xperia Z3 (D6616) and Xperia Z1s (C6916) as “T-Mobile Testing Software Version: Android 5.0 Lollipop“. Back in March, both handsets were at the “Manufacturer Development” stage.
Xperia Z3 owners will also see LTE Band 12 (700 MHz) support with this update. T-Mobile says that this support will be added via a “software update coming May 2015”. Therefore there is every chance that Lollipop is just around the corner, well at least for the T-Mobile Xperia Z3.