Starting today the Windows 10 Anniversary Update will begin rolling out for our customers around the world*.
Note that availability may vary by manufacturer, model, country or region, mobile operator or service provider, hardware limitations and other factors. To manually check for the update, on Start, swipe over to the All apps list, then select Settings > Update & security > Phone update > Check for updates. The Anniversary Update includes additional features and improvements for your Windows 10 phone.
Update 8/16/16: The Windows 10 Anniversary Update has begun rolling out for Windows 10 Mobile.