If you are using Lumia 640 on AT&T, this news is for you. AT&T is rolling out Windows 10 update for Lumia 640. Users have confirmed it on AT&T forum that they are receiving the update.
You need to download Update Advisor to check for the update and it should be ready for you. Don’t forget to backup your mobile to avoid any mishappening.
Are you receiving the update on your Lumia 640? Tell us in the comments.