Windows 10 Mobile will not be rolled out to Windows Phone handsets until next year, with Microsoft stating the upgrades have been pushed back until “early 2016.” Microsoft has released Windows 10 Mobile Build 10586 to those on the Windows Insider Program, but that will be the last build released until January.

This means that while anyone buying a new Lumia 950, Lumia 950XL, or Lumia 550 can start using Windows 10 Mobile right away, anyone using a handset running Windows Phone 8 or Windows Phone 8.1 will have to wait a while longer. How much longer remains unclear, but Microsoft seems determined to get this upgrade right first time.