The Office 365 Admin Center offers the option to bulk-create user accounts. Loading up a CSV file with details and having it processed is simple enough, but the resulting accounts need some work before they are fit for purpose and ready for people to use. Here’s how the bulk creation process works and why we think it has some flaws.
https://office365itpros.com/2019/03/28/bulk-addition-office-365-accounts/
