Most Microsoft 365 tenancies are not broken, they are unowned. Licences drift, sharing is set to whatever the first admin chose, and nobody has looked at the security defaults since go-live.

Where tenancies usually go wrong

Over-licensing is the visible cost. The expensive one is permissions: guest access left open, files shared with anyone who has the link, and mailboxes with delegate rights nobody remembers granting. We audit all three before proposing anything.

Migrating with limited downtime

Mail, files and identity move in staged cutovers with a rollback point at each step. SharePoint and file share migrations are the ones that go wrong quietly: the content copies fine and the permissions do not follow it, so people either lose access on Monday or gain access nobody intended. We map permissions before the move and reconcile them after. Cutover windows are short, scheduled with you and communicated in advance, so people know what will be unavailable and for how long.

What happens after go-live

Licence review each quarter against actual usage, conditional access maintained as staff join and leave, and backup of the tenancy itself, because Microsoft replicates your data but does not protect you from deleting it.