OneDrive for Business Inactivity Report

Hi Andrew,

have you tried the "OneDrive Usage" report in the admin center? This report might be a good starting point as it includes "last activity date" for the individual accounts. You can use the "export" functionality to get to the full list. Please note that the activity on an account can be performed by the owner of the account or also by somebody else. i.e. if I modify a document on my coworker's Brian account that he shared with me, that's also counted as activity.

Thanks,

Anne