Microsoft is delaying the update of Windows 10 Mobile to many Lumia smartphones. This means that most Microsoft Lumia owners will have to wait until 2016 to install the update.

Phones that currently run Windows 8 or Windows 8.1 will not see the Windows 10 Mobile update until "early 2016," TechRadar reports.

Microsoft announced in August that many Lumia smartphones would be receiving the Windows 10 Mobile update by "the end of 2015." The Lumia 430, Lumia 435, Lumia 532, Lumia 535, Lumia 540, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830 and Lumia 930 were all expected to receive the update this year.

Microsoft has continued to delay the Windows 10 Mobile update for these phones and the only two phones that have received the update are the Microsoft Lumia 950 and the Lumia 950 XL.

Once the update is finally available for the older Lumia phones, users will need at least 8 GB of internal storage and be running Windows Phone 8.10.14219.341 or above.

The Windows 10 Mobile build for the Lumia 950 and Lumia 950 XL has seen some startup issues and bugs. Microsoft continued to make fixes to the build and the latest build of Windows 10 Mobile is very solid. It was expected that this build was ready for full release to all of the Lumia devices, but that did not happen.

Microsoft unpublished that build to fix some major issues and only made it available to the Lumia 950 and Lumia 950 XL.

The original thought was for Windows 10 Mobile to be available sometime in September. After a delay, it was thought November and then Microsoft said before the end of 2015. Now, owners of most Lumia devices have to wait until early 2016.

Windows Phones have lagged behind Apple iOS and Google Android phones. Microsoft hopes with Windows 10 Mobile that customers will start buying their devices. The Lumia 950 and Lumia 950 XL are the two latest phones from Microsoft.