Microsoft is delaying the Windows 10 Mobile upgrades for Windows Phone 8 and 8.1 users to early 2016. The company announced earlier in October that the upgrades would come this month.

The company's spokesperson told Venture Beat, that the Windows 10 Mobile upgrade will begin rolling out early next year to select existing Windows 8 and 8.1 phones. This means not a single Windows phone will be upgraded to Windows 10 Mobile in December as the company promised earlier.

The Windows Phone users who looks for the free Windows 10 Mobile upgrade for their existing Windows Phone 8 or 8.1 will have to keep waiting until early 2016. But the Windows Phone fans can try the Microsoft's  latest operating system by helping the company to test new builds through a Windows Insider program.

According to ZDNet, Microsoft has just released a new Cumulative Update for Windows 10 for PCs. The update hit the build number of 10586.36 and the latest cumulative is KB3124200. The new update offers improved functionality for Windows 10 version 1511.

The Windows Insider chief Gabe Aul said that the 10586.36 update is also available to Windows 10 Mobile Insiders. He said that Microsoft plans to notify the Windows Insider participants about the releases of the Cumulative Updates via the Insider Hub.

Microsoft spokesperson said in a statement that the Windows 10 Mobile is currently available for the Microsoft's Lumia 950 and Lumia 950 XL. The company released the two models in November. For the Windows Phone fans who are looking to get the new experience of Windows 10 mobile and looking for a new device, they can choose these two models.

The Windows 10 Mobile upgrade will require a device with a 8GB of internal storage, according to The Verge. That means some Windows Phones like Lumia 530 will be left out. The first devices waiting for Windows 10 upgrade including the Lumia 430, Lumia 435, Lumia 535, Lumia 540, Lumia 635, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830, and Lumia 930.

Microsoft now plans to regularly update the Windows Phone's operating system, alongside the PC version of Windows 10. The company is now able to deliver timely updates to PCs and mobile devices at the same time.

The software maker hit a significant milestone earlier this month when all PCs and phones on the Windows Insider program received the same Windows 10 build.

The new feature that  integrates PCs and phones can roll out to both Windows PCs and mobile handsets at the same time. It will allow the timely updates synchronized to every Windows 10 device with the same software.