Redmond announced earlier this year that Lumia Denim would ship for all devices in the fourth quarter of this year, and now some sources claim that the release is imminent for flagship phones.

New information coming from UK carrier O2 reveals that Microsoft might actually push back the launch of Lumia Denim update for some phones to early 2015, as the Redmond-based software giant is yet to release the update to carriers across the world.

The standard process goes up like this: Microsoft ships the update to carriers for testing and approval for their own devices. Once this step is completed, the new firmware update can be safely shipped to users, and everything is estimated to take at least a couple of weeks if no errors are being found.

In a post on its support forums, O2 confirms that it still hasn't received the Denim from Microsoft, which makes it believe that the update could actually be sent to Windows Phone users in early 2015.

Release could begin this week

The information we have right now indicates that Microsoft might actually begin the Denim rollout sometime this week at least for flagship devices. If we put together all pieces of the puzzle, it's easy to see that the rollout could take up to two months, which could more or less meet O2's schedule and bring the update on a number of devices in early 2015.

But O2's statements could also be an indication that a delay is possible for the majority of devices, so Lumia 930 and 1520 could be the only ones that might receive Denim in 2014.

“It's coming, but we're not expecting Microsoft to release these this year we're afraid, though you should start seeing them push out to Lumia devices in early 2015... Very early - January at present is what's looking likely,” a company representative is quoted as saying.

“We're on standby - as soon as Microsoft are ready to send us these updates for testing & approval, we'll get right on it as quickly as possible. As soon as this process is finished, we'll release the update back to Nokia for the final part - pushing it to you guys, our customers.”

Lumia Denim is quite an eagerly anticipated product because it'll bring improvements to the overall performance of the OS, as well as enhancements to the camera and shooting speed. Obviously, it will also include all Windows Phone 8.1 Update 1 updates, such as live folders and Cortana.