Microsoft has apparently acknowledged that the Windows Phone 8.1 powered devices will be updated to Windows 10 Mobile early next year.

Earlier reports suggested that Lumia handsets running the Windows Phone 8.1 OS will start receiving the latest OS from December onwards. However, Microsoft did not give out an actual release date in December. Now, it’s official that WP 8.1 owners may have to wait until 2016 to experience the brilliant Windows 10, according to Mary Jo Foley of ZDNet.

Even now, Microsoft has not given out the exact month of release in 2016. Instead, “early 2016” is all we got and this means, the roll out could be any time until a reasonable April or even later, according to GSM Arena. So far, Microsoft has not listed all the compatible Lumia handsets that will receive the new OS update at some point.

Nevertheless, sometime in July, an official list made rounds online pointing to the “first batch” of Lumia devices earmarked to receive this update. Here is the list of handsets eligible to receive the Windows 10 Mobile update: Lumia 430, Lumia 435, Lumia 532, Lumia 535, Lumia 540, Lumia 635 (1 GB RAM), Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830 and Lumia 930.

However, it’s worth noting that features of the new OS will vary based on the configurations of the aforementioned handsets. In any case, Microsoft said that a minimum of 8 GB of internal storage space is required to get the new firmware. To top it off, in case Lumia users would like to upgrade to the Windows 10, the handsets should be updated to “Lumia Denim” software update first.

The Windows 10 update comes packed with killer features and many futuristic aspects like the Continuum. It bundles an improved Action Center and a brilliant Microsoft Edge browser, which will apparently offer distraction-free reading experience.

Universal apps like Maps, Calendar and Photos have also been enhanced. Lastly, digital assistant Cortana will apparently be able to communicate with all the devices. Microsoft says, with the help of Cortana, users will be “able to set a reminder on the PC that shows up on the Lumia.”