HTC's current flagship smartphone, the HTC One M9, was announced back in March and was made available on the same month. It succeeded 2014's HTC One M8, one of the company's most successful models to date.

While there are varying reports about whether or not the two handsets will receive Android 5.1.1 Lollipop updates, HTC executives have separately confirmed that both the HTC One M8 and One M9 will be treated with Google's upcoming Android 6.0 Marshmallow operating system (OS).

Keeping true to its OS release trend, the search giant has made the final Android M preview available to its own line of Nexus devices first. In August, Google has given developers the SDK (software development kit) needed to test the OS on the current-generation Nexus 5, Nexus 6, Nexus 9 and Nexus Player. Once developers are done with firmware tests, a public roll out to models from various manufacturers will soon begin.

Although the actual dates for those roll-outs has yet to be announced, it is observed that some companies tend to be consistent in sending out new firmware to their mobile devices early on. Since they previously partnered with Google to produce Nexus models, Samsung, Motorola, LG, Asus, and HTC, are among the first to get fresh Android updates.

The HTC One M9 was running Android 5.0 Lollipop out of the box when it began shipping. Now, the handset is reportedly receiving over-the-air Android 5.1.1 upgrade. However, the software is only available to One M9 units from Verizon.

This is line with what Mo Versi, Vice President for Product Management at HTC, mentioned a few weeks ago that Verizon-registered HTC One M9 devices will soon be upgraded. The OS is said to deliver the needed fix for the dangerous Stagefright exploit along with network roaming support for the 4G LTE bands 3 and 7.

Furthermore, the 5.1.1 Lollipop OS brings in a native Battery Saver, new animations for Quick Settings containing a flashlight functionality, as well as an improvement on the 64-bit ART Runtime complier, which will result to faster startup for the handset's applications. Verizon users may check if the update is already available by heading to the Settings menu > "About" > choose "Software Updates" > and select "Check Now."

For the 2015 flagship's Android 6.0 update, an exact roll out date is still elusive but users can rest assured because Jeff Gordon, an HTC Senior Global Online Communications Manager, already confirmed earlier that the One M9 along with the One M9+ will indeed be upgraded to the much awaited 6.0 Marshmallow OS.

Meanwhile, the device maker's last generation flagship has been previously doubted whether it will receive an Android M update. However, Versi has also provided confirmation that the HTC One M8 will get the update as well.

Once the One M8 receives the Android 6.0 Mashmallow OS, it will reportedly tag the HTC Sense 7 UI along. The HTC Sense is a user interface software that the company places on top of the stock Android OS from Google to make its devices' performance smoother. Versi mentioned that Sense 7 "will be tied to the M release."