One person or provider should be accountable for the overall position. That does not mean they perform every task; it means they can explain who has access, which devices are trusted, which licences are being paid for and what needs attention.
What should have an owner?
- People and accounts
Joining, role changes, secure sign-in and leaving processes. - Licences
Who needs each licence, what it provides and whether unused licences can be removed. - Devices and apps
Which computers and mobiles can reach business data, and which third-party apps remain connected. - Files and sharing
Where important information belongs, who owns it and whether external sharing is still appropriate.
A useful monthly check
Review new and departed staff, privileged accounts, unfamiliar sign-ins, device compliance, connected apps and licence changes. Record the actions and assign an owner. A short repeatable review is more useful than a large audit that is never revisited.
Tide IT includes this kind of ownership in its Microsoft 365 and device support.