Common Conditional Access policy: Require multifactor authentication for device registration
Use the Conditional Access user action to enforce policy when users register or join devices to Microsoft Entra ID. This control provides granularity in configuring multifactor authentication for registering or joining devices instead of a tenant-wide policy that currently exists. Administrators can customize this policy to fit the security needs of their organization.
User exclusions
Conditional Access policies are powerful tools, we recommend excluding the following accounts from your policies:
- Emergency access or break-glass accounts to prevent tenant-wide account lockout. In the unlikely scenario all administrators are locked out of your tenant, your emergency-access administrative account can be used to log into the tenant to take steps to recover access.
- More information can be found in the article, Manage emergency access accounts in Microsoft Entra ID.
- Service accounts and service principals, such as the Microsoft Entra Connect Sync Account. Service accounts are non-interactive accounts that aren't tied to any particular user. They're normally used by back-end services allowing programmatic access to applications, but are also used to sign in to systems for administrative purposes. Service accounts like these should be excluded since MFA can't be completed programmatically. Calls made by service principals won't be blocked by Conditional Access policies scoped to users. Use Conditional Access for workload identities to define policies targeting service principals.
- If your organization has these accounts in use in scripts or code, consider replacing them with managed identities. As a temporary workaround, you can exclude these specific accounts from the baseline policy.
Create a Conditional Access policy
- Sign in to the Microsoft Entra admin center as at least a Conditional Access Administrator.
- Browse to Protection > Conditional Access > Policies.
- Select New policy.
- Give your policy a name. We recommend that organizations create a meaningful standard for the names of their policies.
- Under Assignments, select Users or workload identities.
- Under Include, select All users.
- Under Exclude, select Users and groups and choose your organization's emergency access or break-glass accounts.
- Under Target resources > User actions, select Register or join devices.
- Under Access controls > Grant, select Grant access, Require authentication strength, select Multifactor authentication, then select Select.
- Confirm your settings and set Enable policy to Report-only.
- Select Create to create to enable your policy.
After administrators confirm the settings using report-only mode, they can move the Enable policy toggle from Report-only to On.
Warning
When a Conditional Access policy is configured with the Register or join devices user action, you must set Identity > Devices > Overview > Device Settings - Require Multifactor Authentication to register or join devices with Microsoft Entra to No. Otherwise, Conditional Access policies with this user action aren't properly enforced. More information about this device setting can found in Configure device settings.
