HTC will begin rolling out its Android 6.0 Marshmallow update for unlocked One M8 handsets “within 24 hours.” Those with a locked, carrier-branded device will have to wait until early next year.

Mo Versi, Vice President of Product Management at HTC, confirmed that testing on the One M8’s Marshmallow update “has been completed,” paving the way for its public release. The update “will be sent out within 24 hours,” Versi tweeted this morning.

Given that there aren’t a vast number of unlocked One M8 handsets out in the wild, we expect this update to reach all devices in one hit. And being unlocked, none of them will need to wait for carrier approval first.

Unfortunately, locked, carrier-branded devices will have to wait for that approval, so they won’t get their Marshmallow upgrades until early 2016, Versi says.

Marshmallow for the One M8 brings a whole host of design and performance improvement, plus new features like Doze, the latest Android app permissions, and lots more.

• SourceMo Versi