Previously, a rumor circulating the internet claimed that Windows 10 Mobile would start rolling out on January 12. However, this rumor turned out to be false. But now, it appears that Microsoft has finally triggered the rollout of Windows 10 Mobile update to devices running Windows Phone 8.1, with Polish users in possession of the Lumia 640 on T-Mobile reporting that they're currently receiving the update.

T-Mobile Poland confirms that the firmware version has been bumped to 02177.00000.15184.36002, which is required to run Windows 10 Mobile.

If you're a Lumia 640 owner on the T-Mobile network in Poland, you can head to your settings to check for updates. However, the carrier warns that the update is rolling out in batches to reduce load on Microsoft's servers, so if you're not seeing a notification yet, don't panic.

Today's news comes just a few days after T-Mobile Germany announced details of its Windows 10 Mobile rollout for a range of its Lumia handsets. Like its Polish counterpart, it also noted that the rollout would be staggered, with devices being upgraded over the coming weeks.

Source: T-Mobile Trendy via WMPoweruser