Allowing just anyone to join a device to your tenant is like letting strangers plug into your company’s network without asking who they are. Once enrolled, those devices can sync corporate data and access sensitive resources. By restricting device join to approved security groups, you make sure only trusted people and hardware are welcomed inside.
Rogue devices: Unapproved or personal devices can join your tenant unchecked.
Data exposure: Corporate files may sync onto compromised or unmanaged hardware.
Inconsistent security: Devices without your compliance policies applied weaken your overall defense.
Go to Entra ID Admin Center.
Navigate: Devices > Device settings.
Under Users may join devices to Azure AD, select Selected.
Assign a designated security group (e.g., IT Staff or Authorized Employees).
Confirm that only vetted users belong to this group.
Over-broad group membership: If the security group includes too many people, you’re back to square one.
Guest or contractor accounts: External identities should rarely, if ever, be allowed to join devices.
Hybrid environments: Make sure on-premise device join settings align with Entra ID restrictions.
Audit device join activity
Check Entra ID sign-in and device logs for unexpected enrollments.
Pair with compliance policies
Use Intune or Endpoint Manager to ensure that joined devices meet patching, encryption, and antivirus requirements.
Regularly review security group membership
Keep the list lean and remove dormant or unnecessary accounts.
Enforce conditional access for devices
Require devices to be compliant before granting access to sensitive apps and data.
Restricting who can join devices keeps your tenant clean, controlled, and trustworthy. By limiting enrollment to vetted groups and auditing regularly, you reduce the chance that compromised or rogue devices ever sync a single byte of company data.