Microsoft is working hard to release Windows 10 on PC later next month, but the mobile version of the operating system will be launched after July 29.
Although the Redmond-based company has yet to confirm when exactly Windows 10 Mobile will be released, rumor has it that the new mobile platform might arrive as early as September.
If that happens, Microsoft's new high-end smartphones known as Lumia 940 and Lumia 940 XL should hit shelves soon afterwards.
But what about all the Lumia smartphones that are now available on the market, as people expect Microsoft to offer Windows 10 Mobile updates as soon as the OS gets released.
Even though only a handful of Lumia smartphones have been confirmed to receive Windows 10 Mobile updates, we still don't know when exactly they will be available.
Well, it looks like French carrier SFR has the answer to this question. According to the operator's software updates roadmap for the rest of the year, Windows 10 Mobile should arrive on Lumia smartphones at the end of 2015.
As seen in the image attached, the following Lumia smartphones should receive Windows 10 Mobile update at SFR later this year: Lumia 435, 520, 430, 535, 625, 635, 830, 920, 925, 930, 1020 and 1520.
You probably noticed that some of the latest Lumia smartphones launched by Microsoft are missing from the list such as Lumia 640, Lumia 640 XL and Lumia 735.
Well, these smartphones might not be available at SFR yet, which is why the carrier did not list them for a Windows 10 Mobile upgrade.
It's also worth mentioning that the unlocked versions of these Lumia smartphones might receive Windows 10 Mobile update slightly earlier than the carrier-branded versions.
So, even though we don't have an exact release date for Windows 10 Mobile upgrades, at least Lumia owners know that they should expect the highly anticipated update by the end of 2015.